Archibald, S. B., D. R. Greenwood, R. Y. Smith, R. W. Mathewes, and J. F. Basinger. “Great Canadian Lagerstätten 1. Early Eocene Lagerstätten of the Okanagan Highlands (British Columbia and Washington State)”. Geoscience Canada, vol. 38, no. 4, Dec. 2011, https://journals.lib.unb.ca/index.php/GC/article/view/18964.