Goldblatt & J.C.Manning (Goldblatt & Hutchings) 1995 - Goldblatt P, Manning JC (1995) Phylogeny of the African Genera Anomatheca and Freesia (Iridaceae: Ixioideae), and a New Genus Xenoscapa. Systematic Botany 20: 161-178. doi: 10.2307/2419447.
There is no corrections for Freesia laxa subsp. azurea yet.