• Picasso. Enrique Mallen, ed. Online Picasso Project (OPP). Sam Houston State University. Accessed 2014.
Catálogo completo de la obra de Picasso. Realizado por el doctor Enrique Mallen. The On-line Picasso Project, established in April 1997, is a purely educational, non-profit, academic project supported by research and development grants from Sam Houston State University and Texas A&M University.