Science Citation Index Expanded The online version of Science Citation Index. Provides author, subject, citation and cited reference searches to journal articles, editorials, letters, and book reviews in the sciences. The index covers 5,300 journals and is updated by approximately 16,000 new records every week. Complete author abstracts are also included. Electronic coverage from 1974. Print coverage (Tisch Reference Indexes [SCI] Z7401 .S365) from 1971.     From the Tisch Library homepage, click on Research Tools, then Electronic Resources: A-Z. Choose "S" (Science Citation Index Expanded). Go to the Tisch Library homepage (http://www.library.tufts.edu/ tisch/tisch.html) Click on Research Tools, then Electronic Resources: A-Z. Choose "S" (Science Citation Index Expanded).