We have a number of books available that are excellent sources of information. This 118-page book is the most recent comparative work on the subject. This is an excellent book, with a good overview of the history, discovery in Borneo, ecology, and classification of the species. All of the species are shown in photographs, many with illustrations as well.
Photographs are exceptional, showing flowering plants in situ, including photos of Paph.
This book investigates the Nepenthes of Borneo in detail, treating each of the species, their ecology, where and how they grow, and how they survive, and discussing the threats they face. Charles Clarke has been studying these plants for the last ten years, and has traveled to all corners of Borneo to research this gook. A number of these plants are illustrated here for the first time, and much of the information presented is new to science. Scientists and lay people with an interest in the natural history of Borneo will find this book essential reading. Excellent color photos of all the species and many natural hybrids are shown, with scientific descriptions of habitat as well.