C. F. H. Von Ludwig, “List of exotic trees, shrubs, plants, bulbs; garden flower, forest, and other seeds: imported lately from Germany (Wurtemberg and Hamburg), Holland, &c. by the Danish Ship Norden, Capt. Burd, and the Ionia, Capt. C. Buck”, S. Afr. Q. J., vol. 1, no. 5, pp. 40–45, Oct. 1831, doi: 10.21504/saqj.15.2598.