Free resource bibliographic database dedicated to economics. Over 1,000,000 items of research can be browsed or searched, and over 900,000 can be downloaded in full text. IDEAS is run by the Economic Research Department of the Federal Reserve Bank of St. Louis, USA.

8. Kopernio
Browser plugin in accessing fulltext pdf

9. MatWeb
Free resource tool on searchable online database of engineering materials.

10. NationMaster
Free resource tool on a massive central data source and a way of graphically comparing nations. Allows users to generate maps, graphs, tables and charts of comparative data for a wide range of indicators.

11. Protein Data Bank (PDB)
Free resource tool by the Protein Data Bank archive-information about the 3D shapes of proteins, nucleic acids, and complex assemblies that helps students and researchers understand all aspects of biomedicine and agriculture, from protein synthesis to health and disease.

12. Teaching and Learning Resources - OER
Free resource tool include free audio books, online courses, MOOCs, language courses, movies, textbooks, eBooks.

13. RSC Education
Free resource tool to educate in chemistry teaching and learning

14. Scinapse: Academic search engine
Search engine to find the scientific paper with bibliographic metric (IF, h-index, citation count) users from 1130 university

15. SciTech Connect
Free resource tool in SciTech Connect is Elsevier blog for the science and technology community, run by the Elsevier Science and Technology Books division. It features posts by prominent Elsevier authors, employees, and other industry experts, sorted by subject matter, field of study and interest. Not only will you be able to see a general overview of what’s trending in the science and technology world, but you will also be able to focus on what is most relevant to your line of study or work. Topics covered by SciTech Connect may include author commentary and interviews, additional book content, new research trends, special announcements, and key conference and event information.

16. World Intellectual Property Organization Library
Free access tool that Provides free access to various intellectual property data collections currently hosted by the World Intellectual Property Organization. These collections include Hague, JOPAL (non-patent reference), Madrid and PCT data. Login as guest or create a free account.

17. RSC A-Z
Free resource tool in an alphabetical listing of the Royal Society of Chemistry education resources & research tools

18. Directory of Open Access Scholarly Resources
ROAD is in line with the actions of UNESCO for promoting Open Access to scientific resources. ROAD is complementary to the Global Open Access Portal (GOAP) developed by UNESCO and providing a snapshot of the status of Open Access to scientific information around the world.

19. Directory of Open Access Repositories
OpenDOAR is the quality-assured, global Directory of Open Access Repositories. You can search and browse through thousands of registered repositories based on a range of features, such as location, software or type of material held.

20. Semantic Scholar
Semantic Scholar is a free, AI-powered research tool for scientific literature, based at the Allen Institute for AI.

21. Figshare
Figshare is a repository where users can make all of their research outputs available in a citable, shareable and discoverable manner.

22. MyJournal
Convenient one-stop repository for Malaysian scholarly journals. Free access to full text information of articles where copyright permits

23. Microsoft Academic
Microsoft Academic is a free academic search engine and citation index that is similar to Google Scholar but can be automatically queried. Its data is potentially useful for bibliometric analysis if it is possible to search effectively for individual journal articles.

24. Dimension
All publications and citations are freely available for personal, non-commercial use, together with rich contextual information. Millions of users turn to Dimensions to discover key research, find out who has funded it, and understand its academic and societal impact.

25. Connected Papers
You can use Connected Papers to get a visual overview of a new academic field