by Buong, Nguyen, Lang, Nguyen Duc
Published in Applied mathematics and computation (15.11.2011)

by Lang, Nguyen Duc, Lich, Tran Gia, Duc, Le
Published in Vietnam journal of mechanics (31.12.2006)

by Bui Chi Buu; Pham Thi Thu Ha; Nguyen Viet Cuong; Nguyen Ðuc Thuan, Nguyen Thi Lang
Published in Nong Nghiep va Phat Trien Nong Thon (01.01.2010)