@inbook{Macrobel:SourceID:6526, author = {Mortensen, T.}, note = {from Kier & Lawson (1978)}, title = {A Monograph of the Echinoidea. IV, 2. Clypeasteroida. Clypeasteridæ, Arachnoidæ, Fibulariidæ, Laganidæ and Scutellidæ}, url = {https://www.vliz.be/vmdcdata/macrobel/aphia.php?p=sourcedetails&id=6526}, year = {1948} }