Enlace Permanente
https://bdu3.siu.edu.ar/bdu/Record/paper:paper_0022152X_v24_n4_p1117_Erra%C3%83%C2%A2%C3%82%C2%80%C3%82%C2%90Balsells
https://bdu3.siu.edu.ar/bdu/Record/paper:paper_0022152X_v24_n4_p1117_Erra%C3%83%C2%A2%C3%82%C2%80%C3%82%C2%90Balsells