Map that shows the advance of the rebel faction in the North Front during the Spanish Civil War.  March - September of 1937.
Own work Based on: Arguelles, Mariano Linares; Uslé, Jesús Pindado (1985)       Gran Enciclopedia de Cantabria, I-XI, Santander:  Editorial Cantabria S.A  ISBN:  84-86420-00-8.
Emilio Gómez Fernández