PubMed Journal Database (medical)
Provides abbreviations and full-titles for all journals indexed in PubMed, including all in MEDLINE.
Biological Journals and Abbreviations
Provides the abbreviations, full titles, and links to the electronic version for many biological and medical journals
All That JAS (Journal Abbreviation Sources)
Journal Abbreviation Sources is a registry of Web resources that list or provide access to the full title of journal abbreviations.