1. Allen RG, Pereira LS, Raes D, Smith M (1998) Crop evapotranspiration. FAO Irrigation and Drainage Paper 56. FAO, Rome, Italy, 293pp
2. Chen Guidi and Wu Chuntao (2006) Will the boat sink the water? The life of China’s peasants. Translated by Zhu Hong. Public Affairs Ltd, London, 229pp
3. Ibrahim AA, Stigter CJ, Adeeb AM, Adam HS, Jansen AE (1989) Development and validation of a shaded Piche evaporimeter for the tropics to replace humidity and wind speed data in the aerodynamic term of the Penman equation. In: Proceedings of the 4th Technical Conference on Instruments and Methods of Observation (TECIMO IV), Instruments and Observing Methods Report No. 35, WMO/TD No. 303r Geneva, pp 147–152
4. Ibrahim AA, Stigter CJ, Adeeb AM, Adam HS, Van Rheenen W (1999) On-farm sampling density and correction requirements for soil moisture determination in irrigated heavy clay soils in the Gezira, Central Sudan. Agric Water Manag 41:91–113
5. Ibrahim AA, Stigter CJ, Adam HS, Adeeb AM, Fadl OAA (2000) Farmers’ practices in on-farm irrigation management in the Gezira scheme, Central Sudan. Rural Environ Eng (Japan) 38:20–29