Sirichai Arayarungsarit. 1991. An evaluation of phosphorus balance of Upper Huai Fa Pah watershed after long-term monocropping of maize. Faculty of Graduate Studies, Mahidol University;
Sirichai Arayarungsarit. (1991) An evaluation of phosphorus balance of Upper Huai Fa Pah watershed after long-term monocropping of maize . Mahidol University/Bangkok.
Sirichai Arayarungsarit. An evaluation of phosphorus balance of Upper Huai Fa Pah watershed after long-term monocropping of maize. . Bangkok:Mahidol University, 1991.
Sirichai Arayarungsarit. (1991) An evaluation of phosphorus balance of Upper Huai Fa Pah watershed after long-term monocropping of maize . Mahidol University/Bangkok.