1. Programme plan for improving desert locust survey and control by satellite remote sensing;Roffey,1975
2. Remote sensing techniques and methodologies for monitoring ecological conditions for desert locust population development;Hielkema;FAO/USAID Final Report, GCP INT/349/USA. Rome, Italy,1980
3. Operational environment monitoring and information dissemination by satellites at FAO: the ARTEMIS and DIANA systems;Hielkema,1988