Zhao, Denan, et al. “Development of a Charge Transfer Space Loop to Improve Adsorption Performance in Aerial Electrostatic Spray”. International Journal of Agricultural and Biological Engineering, vol. 13, no. 5, Oct. 2020, pp. 50-55, https://ijabe.migration.pkpps06.publicknowledgeproject.org/index.php/ijabe/article/view/5531.