Wang, Q., Zhao, Z., Wang, X., Li, N., & Zou, S. (2013). A new form of Elongatoolithidae, Undulatoolithus pengi oogen. et oosp. nov. from Pingxiang, Jiangxi, China. Zootaxa, 3746(1), 194–200. https://doi.org/10.11646/zootaxa.3746.1.9