Zachos, L. G. “Holistic Morphometric Analysis of Growth of the Sand Dollar Echinarachnius parma (Echinodermata:Echinoidea:Clypeasteroida)”. Zootaxa, vol. 4052, no. 2, Dec. 2015, pp. 151–179, doi:10.11646/zootaxa.4052.2.1.