Wangyuan, Zong, Wang Jingliang, Huang Xiaomao, Yu Dong, Zhao Yingbiao, and Sean Graham. 2016. “Development of a Mobile Powered Hole Digger for Orchard Tree Cultivation Using a Slider-Crank Feed Mechanism”. International Journal of Agricultural and Biological Engineering 9 (3):48-56. https://doi.org/10.25165/ijabe.v9i3.1784.