Makhmud Mamatkhanovich Bakhromov, Ulmasbek Jumanazarovich Rakhmonov, and Abdujalil Bobir Ogli Otaboev. “Study Of Negative Friction Forces Under Laboratory Conditions”. The American Journal of Engineering and Technology, vol. 2, no. 11, Nov. 2020, pp. 122-3, doi:10.37547/tajet/Volume02Issue11-20.