8Zhao T, Wang A, Chen Y, et al. Prevalence of childhood asthma, allergic rhinitis and eczema in Urumqi and Beijing. J Paediatr Child Health ,2000,36 : 128-133.
9Lee YL, Shaw CK, Su HJ, et al. Climate, traffic-related air pollutants and allergic rhinitis prevalence in middle-school children in Taiwan. Eur Respir J,2003,21:964-970.
10Yang B, Margo EA. Does sampling using random digit dialing really cost more than sampling from telephone directories:Debunking the myths. BMC Med Res Methodol,2006,6:6.
