iData

从28个欧洲国家的615所大学获得793234份开放获取研

对70多个国家的61个数据库及门户进行跨语言搜索。WorldWideScience.org is a global science gateway accelerating scientific discovery and progress through a multilateral partnership to enable federated searching of national and international scientific databases.

小力盘，提供最新kindle|PDF|txt|mobi|epub电子书图书免费下载，以kindle|PDF|txt|mobi|epub为主的电子书免费下载供学习使用。

为科学、技术和医学文献提供在线搜索引擎和租赁服务。DeepDyve is the largest online rental service for scholarly research with thousands of academic publications available at your fingertips.

文津搜索，国家图书馆近2亿条数据图书馆领域元数据统一式搜索

基于开源软件建设学术搜索引擎，近130万篇文献。More than 200 mio. scientfic documents from more than 8000 content providers. BASE is one of the world's most voluminous search engines for academic web resources.