S. R. Hammersburg, S. T. Hasiotis, and R. A. Robison, “Ichnotaxonomy of the Cambrian Spence Shale Member of the Langston Formation, Wellsville Mountains, Northern Utah, USA”, paleocontributions, no. 20, pp. 1–66, May 2018, doi: 10.17161/1808.26428.