The world's most comprehensive database for life science research. It covers journal literature, and original research reports and reviews in biology and all life sciences.

PubMed lists journal articles and more back to 1947. It covers the subjects of medicine, nursing, dentistry, veterinary medicine, health care systems, preclinical sciences, and related areas. Make sure to access PubMed with this link (instead of PubMed.gov) to get free full-text content.

Provides some graphical spectra in the “Substance Detail”. You can also “Explore by Substance”, and limit by getting references associated with "Spectral Properties", then refine again by research topic using the type of spectra.

A database of peer-reviewed research literature from more than 5,000 international publishers. Scopus covers the scientific, technical, medical and social sciences fields, as well as arts and humanities. Scopus includes scholarly journals, book series, conference proceedings, and industry-specific trade publications.

Web of Science contains content from over 12,000 journals worldwide, including over 150,000 conference proceedings. Covers the sciences, social sciences, arts, and humanities, back to 1900. Also has powerful citation analysis tools.