Created this masterlist since most members here are still students and may find this very helpful for a paper or studies. Most of these are Deep Web related, by the way. Feel free to suggest more useful website!
General
BASE
Art
FindSounds
Humanities
Biznar
Sciences
CiteSeerX
General
BASE
- Bielefeld Academic Search Engine
- Service for managing and discovering scholarly references
- U.S. Government open data
- Various academic journals
- 2-week free trial; Pay-to-search
- Directory of Open Access Journals
- Digitalized texted from various libraries around the world
- Search engine for various research papers
- Academic video search engine
Art
FindSounds
- Sound effects search engine
Humanities
Biznar
- Deep Web business search engine
- Collections of original military records
- Digital library of primary sources in American social history from the antebellum period through reconstruction
- Focuses on education, psychology, American history, sociology, religion, and science and technology
- Search engine for the items digitized from The New York Public Library's collections
- Various news aggregator
- Features recent popular texts/pieces in various websites such as various news sites, Reddit, YouTube, Flickr, etc.
- Real-time social media search and analysis search engine
- For an easier way to explain how to works - if you were to type in your username for example, you'll receive results featuring websites where you were mentioned (such as Twitter) recently
- Resources for Medieval Studies
- Recipe search engine
- Features advanced search for ingredients, diets, tastes, allergies, nutrition, techniques, and time
Sciences
CiteSeerX
- Search engine focused on literature in computer and information science
- Deep Web medical search engine
- Search engine for biomedical literature
- Search engine focused on influential news, comment, analysis and research in the Physical Sciences
- Engineering/mathematics/computing-focused search engine
- Features articles, news, job announcements, reports, etc.
- Datebase for various plants
- Real-time multilingual+translating science literature search engine