Be persistent in your searching.
Try both keyword and subject searching
Narrow a search by using subject headings. Locate subject headings by looking at the descriptors associated with pertinent articles and books.
Try these tips to narrow your search.
Try synonyms (AIDS or Acquired Immune Deficiency Syndrome). Can't think of any synonyms? Try an online thesaurus. Try these tips to expand your search
Try both singular and plural forms of words (use a "+" sign in SocSciAbs to search both singular and plurals e.g. religion+). Use an "*" in Academic Search Premier to get a variety of word endings.
If searching a compound word, try it as one word and as two words (e.g. rain forest or rainforest) to see which retrieves the most useful results.
If searching a term with an internal dash, search the term in each database with and without the internal dash (e.g. x-ray vs. x ray) to see which retrieves the most useful results.