==References====External links==*Flora of British Columbia: "Rhamnus purshiana"*Jepson Flora Project: "Rhamnus purshiana"*USDA Plants Profile: "Frangula purshiana"*Documents related to FDA-1978-N-0021 (Formerly 1978N-036L): Cascara OTC
По сведениям базы данных The Plant List (2010):* Flora of British Columbia: "Rhamnus purshiana"* Jepson Flora Project: "Rhamnus purshiana"* USDA Plants Profile: "Frangula purshiana"