Le, Phuc Nguyen, Thi Anh Thu Nguyen, Ngoc Thuy Luong, Van Hieu Nguyen, Hoai Thu Nguyen, and Sura Nguyen. 2015. “Nickel Recovery from Spent Catalyst of Phu My Fertilizer Plant to Prepare Environmental Catalyst for Treatment of CO and C3H6”. Petrovietnam Journal 7 (August), 40 - 48. http://www.pvj.vn/index.php/TCDK/article/view/605.