claimon, Sootin. “Crorp Nutrient Deficiency Observation and Diagnosis Prototype Program of Department of Agriculture [DOA-CropDOD]”. Thai Agricultural Research Journal 10, no. 3 (September 1, 1992): 127–136. accessed October 1, 2026. https://li01.tci-thaijo.org/index.php/thaiagriculturalresearch/article/view/241639.