Collette, J. H., Getty, P. R., & Hagadorn, J. W. (2011). Insights into an Early Jurassic dinosaur habitat: ichnofacies and enigmatic structures from the Portland Formation, Hoover Quarry, Massachusetts, U.S.A. Atlantic Geoscience, 47, Pages 81 – 98. https://doi.org/10.4138/atlgeol.2011.003