1. Allen RG, Smith M, Pereira LS, Perrier A (1994a) An update for the calculation of reference evapotranspiration. ICID Bull 43(2):35–92
2. Allen RG, Smith M, Perrier A, Pereira LS (1994b) An update for the definition of reference evapotranspiration. ICID Bull 43(2):1–34
3. Allen RG, Pereira LS, Raes D, Smith M (1998) Crop evapotranspiration: guidelines for computing crop water requirements. FAO Irrig. and Drain. Paper No. 56, Food and Agricultural Organization of the United Nations, Rome
4. Allen RG, Walter IA, Elliott R, Mecham B, Jensen ME, Itenfisu D, Howell TA, Snyder R, Brown P, Echings S, Spofford T, Hattendorf M, Cuenca RH, Wright JL, Martin1 D (2000) Issues, requirements and challenges in selecting and specifying a standardized ET equation. In: Proceedings of the national irrigation symposium, ASAE, Phoenix, pp 201–208
5. Burman RD, Nixon PR, Wright JL, Pruitt WO (1980) Water requirements. In: Jensen ME (ed) Design and operation of farm irrigation systems, Monograph No. 3, American Society of Agricultural Engineers, St. Joseph, Mich. 189–232