@inbook{Echinoidea:SourceID:141431, author = {Mortensen, T.}, title = {A Monograph of the Echinoidea. V, 2. Spatangoida II. Amphisternata II. Spatangidæ, Loveniidæ, Pericosmidæ, Schizasteridæ, Brissidæ, 593 pp., C. A. Reitzel, Copenhagen.}, url = {https://www.marinespecies.org/echinoidea/aphia.php?p=sourcedetails&id=141431}, year = {1951} }