Dryland management :
Nelson, Ridley,
Dryland management : the "Desertification" problem / Ridley Nelson - - Washington, DC. : World Bank, 1990. - vii, 39p. : 28cm - World Bank technical paper, no. 116 0253-7494 .
Dryland management : the "Desertification" problem / Ridley Nelson - - Washington, DC. : World Bank, 1990. - vii, 39p. : 28cm - World Bank technical paper, no. 116 0253-7494 .