Easy and fast book searcher, create and search your private library.
通过校园网访问使用
Find Free eBooks(基本不用)
PDF Drive - Search and download PDF files for free.
没啥用,搜的内容杂乱,多数...
适合大众的ePub电子书
Online Library and Publication Platform | OAPEN(主要是欧洲学术电子书)