Springer:
- 5,900,017 From 6,106,159 Articles
- 2,577,351 From 3,941,710 Chapters
IEEE:
4,176,425 From 4,219,110
SAGE Collection:
- Ebooks: 3,342 items From 4,012
- Handbooks: 285 From 341 handbooks
- Encyclopedias: 193 From 242
- Dictionary: 3 From 3
Full IGI Global:
- 3,410 reference books
- 180 research journals
- 89 video lectures
EmeraldInsight:
2341 From 2467 Books & Journals
Jaypee Digital:
Book (2036)/Atlas Videos (2021)/Book Videos (1396)/Series Books (349)/Journal (52)/Reference Works (16)/Video Atlas (14)
Wiley Online:
Returned 5123714 Full Text for a sample search of the word "study" From 5267446.
ebrary:
148,665 books
And many other databases...