Journals undeliverable because of incorrect address will be destroyed. Duplicate copies may be obtained, if available, from the Publisher at the regular price of a single issue. Reprints of individual articles are available from the authors or from the Institute for Scientific Information at 1.800.336.4474. Authors needing information on their reprint order may call 1.800.341.2258. For information and prices call 1.800.358.3583.
Prices are available upon request.
All promotional literature must be approved in advance. Bound volumes for volumes 74 and 75 will be available early 1999 to subscribers only. Orders must be received by the Publisher before December 1, 1998. Volume index appears in the June and December issues. It is a condition of publication that manuscripts submitted to this journal have not been published and will not be simultaneously submitted or published elsewhere.