0034-7426 0034-7426 S0034-74262018000200131 10.15446/recolma.v52n2.77153 Spain 00 12 2018 00 12 2018 52 2 131 137

[1] 2010 2 1149-227 [2] 2007 115-24 [3] 1990 50 3 3 207-54 [4] 2005 46 3 3 309-22 [5] 1996 61 1 1 313-7 [6] 2013 63 3 3 577-82 [7] 1994 29 [8] 1993 64 2 2 169-94