Reprint of the 1931 edition, with corrections and a new foreword by Michael Everson.
De Jong called his - heavily revised - edition the sixth ("Dabükot 6"), in line with Schleyer's five editions, 1880-1897.
OBNB doesn't sell books, but you may be able to find a copy at one of these websites:
Wörterbuch der Weltsprache für Deutschsprechende = Vödabuk Volapüka pro Deutänapükans by Arie de Jong. ISBN 9781904808893. Published by Evertype in 2012. Publication and catalogue information, links to buy online and reader comments.
