L.W.Cayzer & Crisp (Klatt) 2004 - Cayzer LW, Crisp MD, Telford IRH (2004) Cladistic analysis and revision of Billardiera (Pittosporaceae). Australian Systematic Botany 17(1): 83. doi: 10.1071/SB03028.
There is no corrections for Billardiera cymosa subsp. pseudocymosa yet.