Obreras Completas, Tomo XVIII 1967
$18 · Offered by Bolerium Books
La Paz, Bolivia: Ediciones Masas, 1996. Single volume of a 41 volume set of the complete works of the Bolivian Trotskyist, 496p., wraps, text in Spanish. Cat.No: 136307
Found via Rare Books Intel, a search across rare-book dealers, auction houses and marketplaces worldwide.