Coba jelasin Lihat pula dari Francisco Largo Caballero dong

Documents on Caballero from "Trabajadores: The Spanish Civil War through the eyes of organised labour" , a digitised collection of more than 13,000 pages of documents from the archives of the British Trades Union Congress held in the Modern Records Centre, University of Warwick

Andy Durgan  The Rise and Fall of Largo Cabellero, International Socialism, 18 (1983)