pnas journal

An empirical law for the rank-order behavior of journal impact factors is found. Using an extensive data base on impact factors including journals on Education, Agrosciences, Geosciences, Biosciences and Environ- mental, Chemical, Computer, Engineering, Material, Mathematical, Medical and Physical Sciences we have found extremely good fits out- performing other rank-order models. Some extensions to other areas of knowledge are discussed.

Proceedings of the National Academy of Sciences of the United States of America (PNAS) is a long running (1915+), highly regarded journal [ISI Impact Factor 10.260-10.896 (1999-2003]. PNAS was one of the early collaborators with the National Library of Medicine in the creation of PubMed Central. Backfile digitization has been completed at PubMed Central for PNAS;