Colectalia dot com is offering free downloads of five SCW philatelic resources:

1. Catalogue of the Vinebre inverted center stamps (1937). Carles Prats.

2. Catalogue of censor marks used in the Republican prisons and labor camps. (Updated Nov 2019)

3. Gerard Apollano. Histoire Postale de la guerre civile d’Espangne secteur Republicain (volume 2) (1987).

4. As above. Volume 2.

5. The Postal History of the Republican Labor Camps and prisons during the Spanish Civil War.