Ermakova , A. , Whiting, C.V., Trout, K. , Clubbe, C. , Terry, M.K. and Fowler, N. 2021. Densities, plant sizes, and spatial distributions of six wild populations of Lophophora williamsii (Cactaceae) in Texas, U.S.A. Journal of the Botanical Research Institute of Texas. 15, 1 (Jul. 2021), 149–160. DOI:https://doi.org/10.17348/jbrit.v15.i1.1057.