Du, Shangfeng, Qi Pan, Yun Xu, and Shushu Cao. 2020. “Comparison of Three Measurement Models of Soil Nitrate-Nitrogen Based on Ion-Selective Electrodes”. International Journal of Agricultural and Biological Engineering 13 (1):211-16. https://ijabe.migration.pkpps06.publicknowledgeproject.org/index.php/ijabe/article/view/3599.