S.E.Dawson & Cheek (Welw. ex Hiern) 2000 - Cheek M, Dawson S (2000) A Synoptic Revision of Belonophora (Rubiaceae). Kew Bulletin 55(1): 63-80. doi: 10.2307/4117761.
There is no corrections for Belonophora coffeoides subsp. hypoglauca yet.