Pichet Satwinit และ Monnipha Sompong. (2009) Opinions toward ill-health effects among people working the nightshift. Thammasat University:ม.ป.ท.Pichet Satwinit และ Monnipha Sompong. 2009. Opinions toward ill-health effects among people working the nightshift. ม.ป.ท.:Thammasat University;Pichet Satwinit และ Monnipha Sompong. Opinions toward ill-health effects among people working the nightshift. ม.ป.ท.:Thammasat University, 2009. Print.