Volunteer workers in education -- Cuba -- History -- 20th century : Maestras voluntarias = Volunteer teachers / the Literacy Project presents ; in collaboration with La Rueda Films, Centro Memorial Dr. Martin Luther King, Jr. Producciones Caminos, 3 Musas Producciones ; dirección/director, Catherine Murphy ; productores/producers, Lilian Lombera, Josué García ; producción/producers, Rubén Carreño, Ángel Piedra