United States. Army. Camp Pena Colorado (Tex.) & United States. National Archives and Records Service. (1974). Camp Pena Colorado, Texas: Letters sent, registers of letters received, endorsements, letters received. National Archives and Records Service.
Chicago-referens (17:e uppl.)United States. Army. Camp Pena Colorado (Tex.) och United States. National Archives and Records Service. Camp Pena Colorado, Texas: Letters Sent, Registers of Letters Received, Endorsements, Letters Received. Washington: National Archives and Records Service, 1974.
MLA-referens (8:e uppl.)United States. Army. Camp Pena Colorado (Tex.) och United States. National Archives and Records Service. Camp Pena Colorado, Texas: Letters Sent, Registers of Letters Received, Endorsements, Letters Received. National Archives and Records Service, 1974.