Sakunyut Sarutanon. (1997) Correlative study of chemical and physical characteristics of soil and their influence on Pinus kesiya tree-rings : case study fo Phu Kradung and Nam Nao National Parks, Thailand. Mahidol University,:ม.ป.ท.Sakunyut Sarutanon. 1997. Correlative study of chemical and physical characteristics of soil and their influence on Pinus kesiya tree-rings : case study fo Phu Kradung and Nam Nao National Parks, Thailand. ม.ป.ท.:Mahidol University,;Sakunyut Sarutanon. Correlative study of chemical and physical characteristics of soil and their influence on Pinus kesiya tree-rings : case study fo Phu Kradung and Nam Nao National Parks, Thailand. ม.ป.ท.:Mahidol University, 1997. Print.