1. Allen, R. G., Pereira, L. S., Raes, D., Smith, M. (1998). Crop evapotranspiration: guidelines for computing crop water requirements. United Nations FAO, Irrigation and Drainage, NY, Paper No. 56. http://www.fao.org/docrep/X0490E/X0490E00.htm.
2. FAO-56 dual crop coefficient method for estimating evaporation from soil and application extensions;Allen;J. Irrigation Drain. Eng. ASCE,2005
3. Allen, R.G., Tasumi, M., Trezza, R., 2006. Benefits from tying satellite-based energy balance to ground-based reference evapotranspiration. International Conference on Earth Observation for vegetation monitoring and water management, Naples, Italy, 10-11 Nov. 2005, AIP Conference Proceedings 852, ISBN 0-7354-0346-5.
4. Satellite-based energy balance for Mapping Evapotranspiration with Internalized Calibration (METRIC)-model;Allen;J. Irrigation Drain. Eng.,2007
5. Satellite-based energy balance for Mapping Evapotranspiration with Internalized Calibration (METRIC)-applications;Allen;J. Irrigation Drain. Eng.,2007