Towards control of desertification in African drylands : problems, experiences, guidelines
· [published jointly by The Commission of the European Communities (CEC), Bundesministerium für wirtschaftliche Zusammenarbeit (BMZ), Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) ; [compiled and prepared by Johannes Kotschi in cooperation with Reinhard Adelhelm ... [et al.]]
Bok Engelsk 1986