Impact Factor
2.62
Estimated influence, citation density, publishing volume, and citation integrity from the analytics table.
Volume, recency, access pattern, and citing-community signals from the journal analytics record.
Recent article records with DOI-first linking and condensed abstracts.
Last issue of each year contains 3-year cumulative subject index.
Issued 1957-68 without vol. numbering.
Also issued online.
Vol. 39, no. 1 (1995)19950517 Notice not published Printed on acid-free paper