Udom Robkob และ Virulh Sa-yakanit. (1987) Exact propagator of a two dimensional system. Chulalongkorn University:ม.ป.ท.Udom Robkob และ Virulh Sa-yakanit. 1987. Exact propagator of a two dimensional system. ม.ป.ท.:Chulalongkorn University;Udom Robkob และ Virulh Sa-yakanit. Exact propagator of a two dimensional system. ม.ป.ท.:Chulalongkorn University, 1987. Print.