ajol has 479 journals, 8635 issues, 98503 abstracts and 93459 full texts available.
website: info A treasure trove for the lovers of academic open source web resources.
Operated by Bielefeld University Library, it is probably one of the most voluminous search engines.
Some information is incomplete; this could be because of time lapse, writer assumptions, or ignorance. We as people know how to filter this information, but search engine algorithms do not.
When you write a research paper, you must remember that the types of sources you use are equally as important as the words you use in the paper.