1. Department of Mathematics, Ohio State University 231 W. 18th Ave., Columbus, OH 43210. cogdell@math.ohio-state.edu
2. Department of Mathematics, The City College of New York Convent Avenue at 138th Street, New York, NY 10031. jjorgenson@mindspring.com
3. Department of Mathematics, University of Sarajevo Zmaja od Bosne 35, 71 000 Sarajevo, Bosnia and Herzegovina. lejlas@pmf.unsa.ba