Kuelekea katika matumizi bora ya rasilimali ya mazingira : mwongozo wa wilaya za Mbulu na Karatu / wahariri: J.G. Mowo na E.M. Nkonya ; [picha: W. van Campen ... et al.]Towards better use of environmental resources : a planning document of Mbulu and Karatu districts, Tanzania / ed.: J. Douwe Meindertsma and Jan J. Kessler ; [photos W. van Campen ... et al.]