0185-2620 0185-2620 S0185-26202007000200139 México 00 12 2007 00 12 2007 34 139 144 1996 297- p.299 2002 24 79-101 1999 79 2 2 211- p. 214 2001 43 1 1 161-4 1994 XIX-432 2001 81 2 2 398-9