Ketkeo Boupha. 1999. Smoking prevalence and its correlates on smoking behavior among male secondary school children in Viantaine Municipality, Lao PDR. Faculty of Graduate studies, Mahidol University;
Ketkeo Boupha. (1999) Smoking prevalence and its correlates on smoking behavior among male secondary school children in Viantaine Municipality, Lao PDR . Mahidol University/Bangkok.
Ketkeo Boupha. Smoking prevalence and its correlates on smoking behavior among male secondary school children in Viantaine Municipality, Lao PDR. . Bangkok:Mahidol University, 1999.
Ketkeo Boupha. (1999) Smoking prevalence and its correlates on smoking behavior among male secondary school children in Viantaine Municipality, Lao PDR . Mahidol University/Bangkok.