Use standard ACS journal title abbreviations in your References section. If you don't know the EXACT abbreviation of a journal title, search the CASSI database to find it, and copy the abbreviation exactly when you cite an article from that journal.
Cite and list references in a consistent, standard format-- ACS format is suggested.
See Ch. 14 of The ACS Style Guide, 3rd ed. available in the reference section of the library. Pay particular attention to citing in your text (page 287) and referencing what you cite (page 290).