谷歌学术/谷歌镜像

清华大学的一站式的文献资源检索系统

开元知海·e读，检索全国高校图书馆的几百万种图书、几千万篇外文期刊

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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.

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