Yang 1992. Appendix: Descriptions of fossils. 7. Trace fossils. Hongfu, Yin; Yang, Fengqing; Huang, Qisheng; Yang, Hengshu; Lai, XulongThe Triassic of Qinling Mountains and neighboring areas., Press of the China University of Geosciences, Place of publication not given., 1992: 1-211. Chapter pagination: 169-173