The orchids of Peninsular Malaysia and Singapore - Seidenfaden, Gunnar 1908-2001 (Olsen & Olsen, 1992)
"A revision of R.E. Holttum: Orchids of Malaya"–"Published in association with the Royal Botanic Gardens, Kew & Botanic Gardens, Singapore"–Contiene un mapa plegado a color en la cubierta