At the completion of this critical bibliography which forms another step in the direction of the realization of the bibliographical project inaugurated in 1955 by Dr. Voorhoeve's survey of the languages of Sumatra, I acknowledge with gratitude the valuable assistance received from various people. I am indebted to my colleagues Prof. Dr. G. W. J. Drewes, Dr. J. Noorduyn, Dr. Th. Pigeaud, Prof. Dr. A. Teeuw and Dr. P. Voorhoeve, who read all or part of the manuscript and who generously put their extensive knowledge of the Java languages at my disposal. Heartfelt thanks are due to Mr. B. J. Hoff and Mr. A. G. Sciarone, both members of my staff, who verified many of the biblio graphical details. I am grateful to the library of the University of Leiden and to the library of the Institute in The Hague because of their readiness in giving me all the facilities I needed for the preparation of this book. Most useful was the cordial assistance received from my colleague Prof. Dr. P. E. de Josselin de Jong, who spent much time correcting the many imperfections of my English text, which greatly promoted the readability of the narrative sections of this survey.
