1. Field methods for the control of trachoma;Tarizzo, M.L.,1973
2. Guide to trachoma control;Dawson, D.R.; Jones, B.R.; Tarizzo, M.L.,1981
3. Blindness and visual impairment in southern Malawi;Chirambo, M.C.; Tielsch, J.M.; KP, Jr, West;Bull WHO,1986
4. Statistical methods for rates and proportions;Fleiss, J.L.,1981
5. The measurement of observer agreement for categorical data;Landis, JR, Koch; G.G.;Biometrics,1977