Wang, Kejian, et al. “Rapid Detection of Chlorophyll Content and Distribution in Citrus Orchards Based on Low-Altitude Remote Sensing and Bio-Sensors”. International Journal of Agricultural and Biological Engineering, vol. 11, no. 2, Mar. 2018, pp. 164-9, https://ijabe.migration.pkpps03.publicknowledgeproject.org/index.php/ijabe/article/view/3189.