How much is enough?
When searching the literature it can be difficult to determine when you've found all the relevant literature. Unfortunatly there are no short cuts to taking the time to search the literature and setup alerts so that you're notified of future publications.
At the very least a cursory search in chemistry should include:
A more thorough search would also include:
Searching library catalog for relevant specialty books: https://libraries.unl.edu
Searching related subject matter in specialized databases such as Medline, PubMed Central, or ArXiv. See the descriptions in A-Z Databases for more specialized databases. Those working in biochemistry may want to check out the Biological Sciences Databases (Articles and Abstracts).
A very thorough search would include:
Quick Search is a keyword search for books, images, journal articles and more.