@Misc{BVPB20150005823, title = "[Escuelas, institutos y otros centros] [Material gr\'{a}fico]", publisher = "[Oviedo] : [Regi\'{o}n]", editor = "[Regi\'{o}n]", URL = "https://bvpb.mcu.es/es/consulta/registro.do?id=492193", year = "1975", }