Available from some providers with title, <Oct. 30, 2007->: PNAS online PNAS
Abbreviated Titles:
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES PROC NATL ACAD SCI USA PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AME PROC NAT ACAD SCI USA P NATL ACAD SCI USA P NAS US NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA PROCEEDINGS PNAS PROC NATL ACAD SCI U S A PROC NAT ACAD SCI U S A PROC. NATL. ACAD. SCI. U. S. A PRONAS Proc. Natl. Acad. Sci. U.S. Am. (Online)