Changes in risk habits and influencing factors in the Taiwan oral cancer screening program - Pattaranan Munpolsri; Chiu-Wen Su; Hsu-Fei Yang; Tsui-Hsia Hsu; Yen-Yu Chou; Li-Ju Lin; Chao-Chun Wu; Sam Li-Sheng Chen; Amy Ming-Fang Yen (PLoS ONE)