Ferguson, C. S., K. Donham, and J. L. Brown. “Cypripedium Fasciculatum (Orchidaceae) Anthesis and Fruit Set in Relationship to Diapriid Activity”. Selbyana, vol. 26, no. 1/2, June 2005, pp. 103-1, https://ojs.test.flvc.org/selbyana/article/view/121390.