Não informado. (1891). Contributions fron the Department of Botany and Rocky Mountain Herbarium. University of Wyoming.
Citação do estilo Chicago (17ª ed.)Não informado. Contributions Fron the Department of Botany and Rocky Mountain Herbarium. Laramie, Wyo: University of Wyoming, 1891.
Citação MLA (8ª ed.)Não informado. Contributions Fron the Department of Botany and Rocky Mountain Herbarium. University of Wyoming, 1891.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.