Here are databases with specific subject coverage that you should search depending on your topic. Clicking the links will open new tabs.
Essential database for biomedicine. Includes citations from MEDLINE and for biomedical articles in life science journals. A product of the National Center for Biotechnology Information.
Documentation and reporting system for ongoing and recently completed USDA research projects in agriculture, food and nutrition, and forestry
The digitized collection of dissertations and theses completed at the University of Tennessee, Knoxville.