This tool is invaluable for finding information from magazines, news articles, and even individuals' public records.
LexisNexis requires a subscription for most people, but if you're a student, you may already have one.
Voice of the Shuttle is another humanities-focused resource curated by humans who share helpful and interesting Deep Web content.
Project Muse lets you search peer-reviewed academic journal articles and e-books about the humanities.
Some of what is on PubMed is indexed by Google, but you can browse and search the website for difficult-to-find articles.
PubMed indexes articles about biomedical topics.
Web of Science indexes a variety of multidisciplinary academic articles and citations.
There are plenty of great databases that contain peer-reviewed and other academic data that isn't completely searchable in Google or Bing, including: Academic databases and archives are some of the most interesting parts of the Deep Web.