This song happens to have several versions, as usual with so many folk songs, depending on the different situations and units. The original (?) song (The Carmela) I heard in Tunis sung by a pretty Spanish student in 1969. It runs like in Sorcha's source, but starting with "el Exercito del Ebro". So also on a disc with songs of the Republican Army recorded by a French team during the war and published about 1937/38.

Wilfried