Foreign databases commonly used for scientific research evaluation include: SCI (Science Citation Index), EI (Engineering Index), and ISTP (Index of Scientific and Technological Conference Proceedings), also known as the three major search tools.

Retrieval tools are a general term for tools and equipment used to report, store and find literature clues. Library catalogs, journal indexes, document databases for computer retrieval, etc. are all search tools. It has three basic functions: reporting documents, storing documents, and retrieving documents. There are two types of search tools: manual search tools and mechanical search tools. Manual search tools refer to printed secondary documents such as catalogs, indexes, and abstracts. Mechanical retrieval tools refer to the technical equipment of electronic computer information retrieval systems.