Adrain, J. M. and Mcadams, N. E. B. (2012) “The Lower Ordovician (upper Floian) bathyurid trilobite Aponileus Hu, with species from Utah, Texas, and Greenland”, Zootaxa. Auckland, New Zealand, 3293(1), pp. 1–67. doi: 10.11646/zootaxa.3293.1.1.