1 Google Scholar
Google Scholar is founded in 2004, it is one of the widely used academic resources for researchers and scholars, a friendly free academic search engine that indexes academic information from various online web resources. The Google scholar lists information across an array of academic resources, mostly are peer-revived. It works in the same manner as Scirus.
2 Directory of Open Access Journals (DOAJ)
Another free search engine for scientific and scholarly resources. The directory offers a huge range of topics within scientific areas of study. It is among the richest sources of scholarly databases with over 8,000 journals are thoroughly peer-reviewed.
3 Education Resources Information Center (ERIC)
ERIC is sponsored of the Institution of Education Sciences (IES) of U.S. Department of Education, allow you to search by topics related to education. Links lead to other sites, where you may have to purchase information, but you can search for full text articles only. The ERIC website is available to the public for searching more than one million citations going back to 1966.
4 Philippine E-Journal
It is free online database that provides a huge of journals published in Philippines, covering the full range of academic disciplines. The objective of the Philippine Journals Online is to give greater visibility to the participating journals, and to the research they convey.
5 Springer
Springer founded in 1843 and nature first published in 1869. It helps researchers find relevant resources, providing links to the full articles, where available on links to where the book or article can be accessed for free.
It was founded in 1944 by Elton Bryson Stephens Sr. EBSCO provides access to over 172,000 dissertation forms 1902 to the present in a variety of subjects. Full texts are provided when available.
CORE aims to aggregate all open access research and facilitate unrestricted access research. CORE harvests research papers from data provides from all over the world including institutional and subjects repositories, open access articles, from thousands and over tens of thousands of journals, collected from 10,079 data providers around the world.
8 Semantic Scholar
This easy-to-use resource uses artificial intelligence to efficiently sort through millions of science related papers based on your search terms. According to the site, although some articles are behind pay walls, the data they have for those articles is limited.
JSTOR is a very well-know resources , offering access to journals, primary sources, and books in a variety of disciplines. You can register for a free account, but many of the articles are behind a pay wall.