Pillsbury, Joanne (1996). "The Thorny Oyster and the Origins of Empire: Implications of Recently Uncovered Spondylus Imagery from Chan Chan, Peru". Latin American Antiquity (באנגלית). 7 (4): 313–340. doi:10.2307/972262. ISSN1045-6635. JSTOR972262.
Pillsbury, Joanne (1996). "The Thorny Oyster and the Origins of Empire: Implications of Recently Uncovered Spondylus Imagery from Chan Chan, Peru". Latin American Antiquity (באנגלית). 7 (4): 313–340. doi:10.2307/972262. ISSN1045-6635. JSTOR972262.
Pillsbury, Joanne (1996). "The Thorny Oyster and the Origins of Empire: Implications of Recently Uncovered Spondylus Imagery from Chan Chan, Peru". Latin American Antiquity (באנגלית). 7 (4): 313–340. doi:10.2307/972262. ISSN1045-6635. JSTOR972262.