1. Andrews, A. P. 1972. “A preliminary study of U‐shaped structures at Chan Chan and vicinity, Peru”. Harvard University. Unpublished B.A. thesis
2. The U-Shaped Structures at Chan Chan, Peru
3. Brennan, C. T. 1948. “Investigations at Cerro Arena, Peru”. Ann Arbor: University Microfilms. Ph.D. thesis, University of Arizona.