Ishida, Hiroshi. 1993. Techniques to improve productivity of the sandy upland soil on northeast Thailand. Khon Kaen:Agricultural Development Research Center in Northeast;
Ishida, Hiroshi. (1993) Techniques to improve productivity of the sandy upland soil on northeast Thailand (รายงานผลงานวิจัย). Agricultural Development Research Center in Northeast:Khon Kaen.
Ishida, Hiroshi. Techniques to improve productivity of the sandy upland soil on northeast Thailand. Khon Kaen:Agricultural Development Research Center in Northeast, 1993.
Ishida, Hiroshi. (1993) Techniques to improve productivity of the sandy upland soil on northeast Thailand (รายงานผลงานวิจัย). Agricultural Development Research Center in Northeast:Khon Kaen.