Hitchcock, Anthony. “Biogeographical Principles in Horticulture : Creating an Erica and Fynbos Gardenn for Education and Amenity”. Sibbaldia: the International Journal of Botanic Garden Horticulture, no. 17 (February 5, 2019): 101–120. Accessed July 3, 2024. https://journals.rbge.org.uk/rbgesib/article/view/269.