APA
Sombatpanit S., . (1997). Soil conservation extension. New York: Science.
Chicago
Sombatpanit Samran, . 1997. Soil conservation extension. New York: Science.
Harvard
Sombatpanit S., . (1997). Soil conservation extension. New York: Science.
MLA
Sombatpanit Samran, . Soil conservation extension. New York: Science. 1997.