Bui Viet Duc, Ngo Van Tu, Bui Trong Khai, Dang Cua, Bui Viet Phuong, Vu Van Hung, Hoang Hong Linh, Bui Van Thom, and Nguyen Xuan Thao. “Research and Field-Trial of ‘KCl-Protex Sta’ Drilling Mud System and Using Protex Sta in Combination With CFL-AKK-KCl-PAG, KGAC Drilling Mud Systems to Improve Well Drilling Efficiency ”. Petrovietnam Journal, Vol. 4, Apr. 2019, pp. 23-29, doi:10.25073/petrovietnam journal.v4i0.251.