@article{QUE_1993_1993_1_a10,
     author = {Carreras, Francesc},
     title = {Cooperaci\'on y defensa.},
     journal = {Q\"uestii\'o},
     pages = {103-134},
     publisher = {mathdoc},
     volume = {17},
     number = {1},
     year = {1993},
     language = {es},
     url = {http://geodesic.mathdoc.fr/item/QUE_1993_1993_1_a10/}
}