Google Scholar is an academic search engine that indexes scholarly literature from a variety of publication types and fields. Its results are often more dependable and relevant than those provided by other search engines such as Google.

One of the most valuable aspects of Google Scholar is that it enables you to carry out a comprehensive search of scholarly literature from one place. You can access a wide range of materials from academic publications, professional associations, online repositories, universities, and other websites. Google Scholar makes it simple to search for relevant material in the field of scholarly study, whether you're looking for articles, theses, books, abstracts, or court judgments. To rank documents, Google Scholar utilizes a system that is similar to how researchers do. It weighs the full text of each document, its publisher, author, and how frequently and recently it has been cited in other scholarly literature. This ranking system ensures that the search results are accurate and reliable.

Apart from searching scholarly literature, Google Scholar has other useful features. For instance, you can explore related works, citations, authors, and publications. You can also locate complete documents through your library or on the web, stay updated on recent developments in any field of research, check who is citing your publications, and create a public author profile.

Website: https://scholar.google.com/

ERIC (Education Resources Information Center) is a digital collection of education research and information supplied by the Institute of Education Sciences (IES) of the United States. Department of Education. It offers access to bibliographic records of education-related literature from 1966 to the present, including journal and non-journal materials. The mission of ERIC is to provide an easily searchable, comprehensive database of education research and information for students, educators, researchers, policymakers, librarians, parents, and the public.

ERIC’s collection contains over 1.6 million bibliographic records, including journal articles, books, conference papers, research syntheses, policy papers, technical reports, and other education-related materials. ERIC indexes over 1,000 journals, comprehensively for most articles, and selectively for some. Furthermore, there are approximately 350,000 full-text items available, including grey literature such as conference papers and reports, as well as an increasing number of journal articles and books.

ERIC works with publishers and organizations worldwide to provide education research to its users. ERIC adds metadata to publisher-provided content to make it searchable and, whenever possible, makes the PDF and/or link to purchase the article available. Over half a million users visit the ERIC website each week, with many more searching through ERIC data using vendor sites.

Website: https://eric.ed.gov/

Wolfram Alpha is a semantic search engine that was invented by Stephen Wolfram with the goal of providing specific answers to queries. Unlike Google, Wolfram Alpha does not provide hyperlinks with snippets but rather, the search engine offers a compilation of facts as specific results. It is a "computational knowledge engine" that aims to make all systematic knowledge immediately computable and accessible to everyone.

Wolfram Alpha has been able to handle particular inquiries since its inception in 2005 and is regarded as a pioneer of semantic search. The system works by providing complete lists and tables instead of crawlers and indexes that create hyperlinks. Wolfram Alpha can also be used to find academic articles by simply typing in keywords, and it generates a list of academic articles that match the query, ranked by relevance.

Wolfram Alpha's mission is to collect and curate all objective data, apply every known model, technique, and algorithm, and calculate everything that can be computed. The search engine makes expert-level information and capabilities available to the widest possible range of people, regardless of occupation or level of education. It seeks to take entirely free-form input and provide strong outcomes that are presented as clearly as possible.

Website: https://www.wolframalpha.com/

BASE (Bielefeld Academic Search Engine) is a highly comprehensive search engine that specializes in academic web resources. It is managed by Bielefeld University Library and offers access to over 300 million documents from more than 10,000 content providers. Nearly 60% of these documents are freely accessible in entirety due to open-access policies.

The resources indexed by BASE are academically relevant and include journals, digital collections, and institutional repositories that have an OAI interface and use OAI-PMH to provide content. The service is continuously updated with new sources and content providers. What makes BASE over commercial search engines is the careful selection process used to identify content providers, which involves the assessment of the academic quality and relevance of the documents they provide. This ensures that only high-quality and relevant content is included in the index.

BASE also offers several features that enhance the search experience. For example, the search interface is multilingual, allowing users to search for content in over 20 languages. The search results display precise bibliographic data, and users can sort the results list by author, title, or date. Author, subject, year of publishing, content provider, language, document type, access, and re-use terms can also be used to filter the results.

Website: https://www.base-search.net/

CORE is the largest collection of open-access research papers globally, collecting and indexing research from both repositories and journals. The non-profit service is dedicated to the open access mission and is a signatory to the Principles of Open Scholarly Infrastructures.

CORE provides services to a worldwide network of repositories and journals by boosting discoverability and avoiding content abuse. It makes metadata records uniquely identifiable and resolvable with decentralized PIDs and provides tools for metadata validation, content management, enrichment, and OA compliance to support data providers in adopting good practices. CORE also facilitates machine access to open research.

CORE's services are designed to support a wide range of stakeholders, including researchers, the general public, academic institutions, developers, funders, as well as companies from various sectors, such as innovators, AI technology firms, digital library solutions, and pharmaceutical companies. The portal collects academic articles from institutional and topic repositories, as well as open-access and hybrid publications. CORE also uses state-of-the-art text and data mining technologies to enrich scholarly data, aid discoverability, and enable others to develop new tools and use cases on top of the CORE platform. Currently, CORE holds over 239 million open-access articles collected from 11,000 data providers worldwide.

Website: https://core.ac.uk/

Science.gov is a free, government-operated online gateway to research and development results and scientific information. The platform grants access to a vast array of federal science information in many formats, including full-text documents, citations, scientific data, and multimedia.

Science.gov consolidates over 60 databases, 2,200 websites, and over 200 million pages of science information from 13 federal agencies. It also provides access to free journal articles, peer-reviewed manuscripts, and reports of federally funded research, as well as information on public access policies and requirements. Moreover, Science.gov offers information from across the federal government on education and training opportunities in science, technology, engineering, and mathematics (STEM) fields for undergraduate and graduate students. The platform is available for free and does not require registration.

Science.gov is a model of interagency collaboration launched in 2002 to provide a public infrastructure for accessing the U.S. government's scientific research information. The website was developed and is maintained by the DOE Office of Scientific and Technical Information, a unit of the Office of Science. Science.gov is supported by CENDI, an interagency working group of senior scientific and technical information managers. Science.gov is governed by the interagency Science.gov Alliance, which includes the Departments of Agriculture, Commerce, Defense, Education, Energy, Health and Human Services, Homeland Security, and Transportation; the Environmental Protection Agency, the National Aeronautics and Space Administration, the National Science Foundation, and the U.S. Government Publishing Office.

Website: https://www.science.gov/

Semantic Scholar is an AI-driven search engine for academic papers, providing free and open resources to the global research community. It indexes over 200 million academic publications via publisher collaborations, data sources, and web crawls. The Allen Institute for Artificial Intelligence (AI2) established the initiative in 2015 to assist researchers in keeping up with reading all of the articles in their areas.

The purpose of Semantic Scholar is to automate learning from text to overcome information overload, and to provide more relevant and effective search results through artificial intelligence-powered methods that detect hidden relationships and connections between research topics. The platform saves users time by limiting the results, and provides a few hundred directly relevant search results, unlike Google Scholar and PubMed which often return tens of thousands of results. Semantic Scholar also removes the distraction caused by less relevant research.

Semantic Scholar is designed by researchers for researchers, with features such as full-text and mobile-enabled design to save time. The platform's mission is to renew a scientist's joy of discovery once again, by limiting the long tail of search results and enabling quick updates on disciplines. Semantic Scholar is a recent entrant to the field and provides a user-friendly interface for easy access to academic papers.

Website: https://www.semanticscholar.org/

RefSeek is a search engine designed for students and researchers to easily access academic information. Its comprehensive search covers over 5 billion documents, including books, journals, newspapers, and web pages. Unlike general search engines, RefSeek uses a unique approach to provide students with relevant subject coverage without overwhelming them with commercial results.

With RefSeek, students can explore research ideas from unexpected angles and discover new databases they may not have known about before, such as the CIA World Factbook. It is user-friendly, having a clean and straightforward interface that makes it simple to get started. The Documents tab is easy to use and offers filtered results by date, document type, and language. Additionally, RefSeek offers a variety of export formats, including BibTeX, Endnote, RefWorks, and Zotero.

RefSeek is currently in public beta and offers a solid choice for general research. The search engine takes a website-based approach, bringing up relevant and dependable websites related to your search topic. RefSeek also features a directory page with useful websites related to education for specific fields of study. When you choose a category to peruse, RefSeek provides a list of useful websites to assist you in studying and researching the information you want.

Website: https://www.refseek.com/

WorldWideScience.org is an online global science gateway that aims to provide users with the most up-to-date scientific findings from around the world. It is made up of national and international scientific databases and portals, and maintained by the U.S. Department of Energy's Office of Scientific and Technical Information (OSTI) collaborated with the International Council of Scientific and Technical Information (ICSTI). It allows users to search multiple scientific sources using a single query. The portal offers translations in ten languages, making it accessible to users worldwide. Science-related fields including energy, medicine, agriculture, environmental sciences, and engineering are all covered.

To give comprehensive coverage of worldwide science and research achievements, WorldWideScience.org employs federated search. This means it delves into the deep web, which holds a wealth of scientific and technological data. To search WorldWideScience.org, users enter a query in their preferred language, and the portal sends it to every individual database or portal connected to it, using both federated search and multilingual translation technologies. The databases and portals then send back a list of results ranked in order of relevance. National and international scientific databases and portals that engage in WorldWideScience.org gain from improved usage and distribution of their scientific and technical information, as well as collaboration and networking with top science libraries and information centers.

Website: https://worldwidescience.org/

CiteSeerX is an innovative digital library and search engine for scientific literature that focuses mostly on computer and information science literature. It aims to improve the dissemination of scientific literature by providing improvements in functionality, usability, availability, cost, comprehensiveness, efficiency, and timeliness in the access to scientific and scholarly knowledge.

CiteSeerX has created new methods and algorithms for indexing PostScript and PDF research publications available on the Internet. One of the unique features of CiteSeerX is the citation statistics. Every search result informs you how many times an author's work has been referenced in the bibliographies of other writers. Additionally, users can explore the linked papers of other authors in detail. Users can browse abstracts and keywords, see a cached PDF of full-text publications, or click on download links for papers of interest.

CiteSeerX's powerful search engine makes it easy for users to search for authors by their full names, partial names, or initials. Users can perform a basic search, or they can limit their search terms by date ranges, publishers, or author affiliations. The platform is designed to be user-friendly and easy to use, ensuring that users can quickly and easily find the information they need.

Website: https://citeseerx.ist.psu.edu/