BURTON-KELLY, M.E. and J.M. ERICKSON. 2010. A new occurrence of Protichnites Owen, 1852, in the Late Cambrian Potsdam Sandstone of the St. Lawrence Lowlands. The Open Paleontology Journal 3:1-13.
You can download a PDF from here 1MB. You can follow this publication on Academia.edu or ResearchGate.