Ogunbodede, Olabode; McCombs, Douglas; Trout, Keeper; Daley, Paul; Terry, Martin (2010-09-15). "New mescaline concentrations from 14 taxa/cultivars of Echinopsis spp. (Cactaceae) ("San Pedro") and their relevance to shamanic practice". Journal of Ethnopharmacology. 131 (2): 356–362. doi:10.1016/j.jep.2010.07.021. PMID20637277.
Ogunbodede, Olabode; McCombs, Douglas; Trout, Keeper; Daley, Paul; Terry, Martin (2010-09-15). "New mescaline concentrations from 14 taxa/cultivars of Echinopsis spp. (Cactaceae) ("San Pedro") and their relevance to shamanic practice". Journal of Ethnopharmacology. 131 (2): 356–362. doi:10.1016/j.jep.2010.07.021. PMID20637277.