Citation: Pfeffer K-h et Yongvanit T.s, The karst Region Khon San in Northeast Thailand, Zeitschrift fur Geomorphologie. Supplementband Zeitschrift fur Geomorphologie. Supplement;Zeitschrift fur Geomorphologie. Supplementary issue Annals of geomorphology. Supplement;Annales de geomorphologie. Supplement, 147, 2007, pp. 77-106