Chemical Literature is Historically Classified into Three Types of Sources written by Dr. David Hunt and updated by Valerie Tucci
1. Primary Sources
Journals or Periodicals
Technical Reports - Government or Industry
Patents - U.S. or Foreign
Dissertations
2. Secondary Sources
Periodicals (Reviews) - Chemical Reviews, Chemical Society Reviews
Abstracting and Indexing Sources - Chemical Abstracts (SciFinder Web), Web of Science
Handbooks, Dictionaries and Encyclopedias - CRC Handbook of Chemistry and Physics,
Kirk-Othmer Encyclopedia of Chemical Technology
Data Collections - Beilstein and Gmelin - now online as Reaxys
Treatises and Monographs
Textbooks
3. Tertiary Sources
Catalogs - Sigma-Aldrich, Lancaster Synthesis, Alfar Aesar, Acros Organics