Perrett, H. E. (1984). MONITORING AND EVALUATION OF COMMUNICATION SUPPORT ACTIVITIES ON LAW-COST SANITATION PROJECTS. Unido.
Čikaški stil citiranja (17. izdanje)Perrett, Heli E. MONITORING AND EVALUATION OF COMMUNICATION SUPPORT ACTIVITIES ON LAW-COST SANITATION PROJECTS. Unido, 1984.
MLA način citiranja (8. izdanje)Perrett, Heli E. MONITORING AND EVALUATION OF COMMUNICATION SUPPORT ACTIVITIES ON LAW-COST SANITATION PROJECTS. Unido, 1984.
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