Proceedings National Academy of Sciences (PNAS) Liberalization of PNAS copyright policy: Noncommercial use freely allowed Note original Author should be contacted for permission to reuse for Educational purposes. See also PNAS Author Rights and Permission FAQs
- Cozzarelli NR, Fulton KR, Sullenberger DM. Liberalization of PNAS copyright policy: noncommercial use freely allowed. Proc Natl Acad Sci U S A. 2004 Aug 24;101(34):12399. PMID15314225 "Our guiding principle is that, while PNAS retains copyright, anyone can make noncommercial use of work in PNAS without asking our permission, provided that the original source is cited."