Qing, Tang, et al. “Droplets Movement and Deposition of an Eight-Rotor Agricultural UAV in Downwash Flow Field”. International Journal of Agricultural and Biological Engineering, vol. 10, no. 3, May 2017, pp. 47-56, https://ijabe.migration.pkpps06.publicknowledgeproject.org/index.php/ijabe/article/view/3075.