Cita APA (7a ed.)

Roberts, F. H. H. (1930). Early pueblo ruins in the piedra district, Southwestern Colorado. Government Printing Office.

Cita Chicago Style (17a ed.)

Roberts, Frank H. H. Early Pueblo Ruins in the Piedra District, Southwestern Colorado. Washington: Government Printing Office, 1930.

Cita MLA (8a ed.)

Roberts, Frank H. H. Early Pueblo Ruins in the Piedra District, Southwestern Colorado. Government Printing Office, 1930.