TY - JOUR A1 - Lau, J.T. A1 - Tsui, H.Y. A1 - Wang, Q.S. T1 - Effects of two telephone survey methods on the level of reported risk behaviours Y1 - 2003 DO - 10.1136/sti.79.4.325 JF - Sexually Transmitted Infections VL - 79 IS - 4 SP - 325 EP - -331 ER -