The Echinoderms newsletter - National Museum of Natural History (U.S.). Department of Invertebrate Zoology (Echinoderms) (Dept. of Invertebrate Zoology (Echinoderms), National Museum of Natural History, Smithsonian Institution, 2001)

Echinoderms of Connecticut - Coe, Wesley R. (Wesley Roswell), 1869 -1960 (Printed for the State Geological and Natural History Survey, 1912)

Echinoderms of Connecticut - Coe, Wesley R. (Wesley Roswell), 1869 -1960 (Printed for the State geological and natural history survey, 1912)

Die Echinoidea der Siboga-expedition - Meijere, J. C. H. de (Johannes Cornelis Hendrik) 1866 -1947 (Buchhandlung und druckerei vormals E. J. Brill, 1904)

Echinoidea Pt. I-II - Mortensen, Theodor, 1868 -1952 (Printed by Bianco Luno, 1903)