1982-7806 1982-7806 S1982-78062017000200408 10.14393/che-v16n2-2017-6 Spain 00 08 2017 00 08 2017 16 2 408 433

11 44 44 9 231-39 22 22 55-79 4 159 159 4- 39 39 13-25