About Maria Elena de Valdes MARIA ELENA DE VALDES has taught in the Spanish Section of the Division of Language Training, York University, Toronto. Books by Maria Elena de Valdes An Unamuno Source Book A catalogue of readings and acquisitions with an introductary essay on Unamuno's dialectical enquiry by (author) Mario Valdes & Maria Elena de Valdes An Unamuno Source Book A catalogue of readings and acquisitions with an introductary essay on Unamuno's dialectical enquiry by (author) Mario Valdes & Maria Elena de Valdes