@article{STO_1979_1979_1_a2,
     author = {Pla Carrera, Josep},
     title = {Formalizaci\'on del sistema {S1} de {Lewis} sin reglas de sustituci\'on.},
     journal = {Stochastica},
     pages = {39-45},
     year = {1979},
     volume = {3},
     number = {1},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/STO_1979_1979_1_a2/}
}