LLIFLE – Encyclopedia of living forms, Encyclopedia of Succulents, Crassula ericoides page. Accessed on 2019/08/08. http://www.llifle.com/Encyclopedia/SUCCULENTS/Family/Crassulaceae/27360/Crassula_ericoides
http://pza.sanbi.org/references/llifle-–-encyclopedia-living-forms-encyclopedia-succulents-crassula-ericoides-page