Physics Department, University of Szczecin, Wielkopolska 15, 70-451 Szczecin, Poland; fferrari(at)univ.szczecin.pl
Received 11 May 2001, revised 28 October 2001, accepted 5 November 2001 by U. Eckern
(1) Laboratoire de Physique Quantique, Universite Paul Sabatier; (2) Inst. f. Theor. Physik, Uni Erlangen; (3) Lab. d. Phys. Quantique, Univ. P. Sabatier
Received 17 July 2001, accepted 19 October 2001 by G. Röpke
Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211, USA; MashhoonB(at)missouri.edu
Received 2 November 2001, accepted 8 November 2001 by F. W. Hehl