Charles Clarke
"Nepenthes of Sumatra and Peninsular Malaysia"

Natural History Publications (Borneo) Sdn. Bhd., Kota Kinabalu, Sabah, Malaysia, 2001. ISBN 9838120502, hardcover

Description:

in English,
X + 326 pp., 147 color photographs, 4 color maps, 6 drawings/graphs

From the contents

The chapter on the species goes into far greater taxonomic detail than Nepenthes of Borneo, with a similar format to that used by Jebb & Cheek in their 1997 revision of the genus. An excellent treatment of Nepenthes in the covered region.
Review CPN 31(1), 2002, p. 9 by Jan Schlauer: "I recommend it without any reservation."