1. Haematological investigation in Umm Gozein, Kordofan Province, Sudan;Ahmed;Sudan med. J.,1968
2. Present and future state of treated wastewater and sewage sludge in Tunisia;Bahkri,1991
3. Health aspects of nightsoil and sludge use in agriculture and aquaculture Part III: an epidemiological perspective;Blum,1985
4. Statewide standards for the safe direct use of reclaimed wastewater for irrigation and recreational impoundments;California State Department of Public Health,1968
5. Recommandations Sanitaires concernant l'Utilisation des Cultures et des Espaces Verts;Conseil Supéricur d'Hygiene Publique de France,1991