Coppard, S. E. (2008). A comparative analysis of the spatangoid echinoid genera Brissopsis and Metalia: a new genus and species of spatangoid (Echinodermata: Echinoidea: Brissopsidae) from the Philippines and the reassignment of Brissopsis persica to Metalia. Zootaxa, 1760(1), 1–23. https://doi.org/10.11646/zootaxa.1760.1.1