Impact Factor
3.14
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.
Cumulative author and subject indexes:
Vols. 1-15, 1956-67, with v.15.
Vols. 16-30, 1967-70, with v.30.
Author and subject indexes published annually, 1973-
Also issued online.
Articles in English, French, or German; summaries in these three languages and Russian.
Vol. 183, no. 1 (JUL 31 1989)19900914 Notice published Printed on acid-free paper