Lieberman, B. S. (2002): "Phylogenetic analysis of some basal early Cambrian trilobites, the biogeographic origins of the eutrilobita, and the timing of the Cambrian radiation", Journal of Paleontology76 (4): 692–708. Resumo e referencias.
ohio-state.edu
www1.newark.ohio-state.edu
Robert Kihm; James St. John (2007). Donald G. Mikulic, Ed Landing and Joanne Kluessendorf, ed. "Walch's trilobite research – A translation of his 1771 trilobite chapter"(PDF). New York State Museum Bulletin. Fabulous fossils – 300 years of worldwide research on trilobites (University of the State of New York) 507: 115–140. Arquivado dende o orixinal(PDF) o 20 de xullo de 2011. Consultado o 14 de xaneiro de 2013.
Robert Kihm; James St. John (2007). Donald G. Mikulic, Ed Landing and Joanne Kluessendorf, ed. "Walch's trilobite research – A translation of his 1771 trilobite chapter"(PDF). New York State Museum Bulletin. Fabulous fossils – 300 years of worldwide research on trilobites (University of the State of New York) 507: 115–140. Arquivado dende o orixinal(PDF) o 20 de xullo de 2011. Consultado o 14 de xaneiro de 2013.