CAS SciFinder-n is the latest scientific information solution from CAS, a division of the American Chemical Society. In addition to the reference, substance, reaction and supplier content found in CAS SciFinder®,
CAS SciFinder-n includes relevance-ranked results, step-by-step procedures and protocols, citation mapping, biosequence searching, retrosynthetic analysis, patent landscape mapping, touch-screen enabled structure drawing and much more—all accessible in a simple, easy-to-use interface. (Drew users only. Go HERE to learn about how to register for a CAS SciFinder Account.)

PubMed comprises more than 23 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.

3 major citation indexes covering the Sciences, the Social Sciences and Arts & Humanities. Start with a known article and find other articles that have cited it. Also useful for interdisciplinary keyword searching.