http://www.pnas.org/ Download this publisher's e-journal holdings (xlsx) Content Type OA ? PCA ? Journals No Yes Request a holdings comparison Portico provides a free holdings comparison service to compare a library’s journal or book holdings to the Portico archive. Search titles and ISSNs by keyword: Show: E-Journals All0-9ABCDEFGHIJKLMNOPQRSTUVWXYZ Titles start with P (1) ISSN Status Proceedings of the National Academy of Sciences 0027-8424, 1091-6490 preserved