The material includes the collection of a number of sources: the works themselves and sources with sound (recordings, interviews, etc.), and also oral, written (archival, newspaper libraries and bibliographic) and visual (filmings). Consultation and visits to various libraries, archives, collections and museums spread between Spain and the United States primarily were required to locate them.

Finally, as to the methodology used, this combines different aspects of the artistic and historical studies, such as the biographical reconstruction, formalism, the iconography-iconology and the sociology of art.