Von Ludwig, C. F. H. 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. 1831, 1 (5), 40-45. https://doi.org/10.21504/saqj.15.2598.