Impact Factor
2.51
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.
Print issues ceased with v. 18, no. 4 (2007).
Also issued online.
Vol. 2, no. 1 (1991)19920916 Notice not published Printed on acid-free paper