Urania, Berlin / TU Berlin, Germany; ubleyer(at)urania-berlin.de,
borzeszk(at)itp.physik.tu-berlin.de
Institute of Physics, University of Szczecin, Wielkkopolska 15, 70-451
Szczecin, Poland; mpdabfz(at)sus.univ.szczecin.pl
Received 11 Sep 2006, accepted 27 Oct 2006 by F. W. Hehl
Departamento Matematica Aplicada, Facultad de Ciencias, Universidad de
Valladolid, Valladolid, 47005, Spain; jfpascua(at)maf.uva.es
Received 14 Mar 2006, revised 3 Nov 2006, accepted 7 Nov 2006 by F. W. Hehl
Instituto de Fisica, Universidade de Sao Paulo, Caixa Postal 66318-CEP,
05315-970 Sao Paulo, S. P., Brazil; bagrov(at)phys.tsu.ru, baldiott(at)fma.if.usp.br
Received 9 Aug 2006, revised 1 Nov 2006, accepted 8 Nov 2006 by B. Kramer
Institute of Strength Physics and Materials Science, Siberian Branch of Russian
Academy of Sciences, Tomsk-21, 634021, Russia; lbz(at)ispms.tsc.ru
Received 26 May 2006, revised 17 Nov 2006, accepted 17 Nov 2006 by U. Eckern
Instituto Politecnico Nacional, Sezyon Estudios Posgrado & Invest Escuela Super I,
Edif Z-4, 3er Piso, Col Lindavista, Mexico City 07738, DF Mexico; jlopezb(at)ipn.mx
Received 8 Oct 2006, revised 22 Nov 2006, accepted 26 Nov 2006 by F. W. Hehl