Goyder DJ, Liede-Schumann S (2008) Notes on Cynanchum and Pentarrhinum (Apocynaceae: Asclepiadoideae) in tropical Africa. Kew Bulletin 63(3): 463-466. doi: 10.1007/s12225-008-9048-4.
There is no corrections for Cynanchum gerrardii subsp. lenewtonii yet.