1. Allen, R.G., Pereira, L.S., Dirk, R., Smith, M., 1998. Crop evapotranspiration: guidelines for computing crop water requirements. FAO Irrigation and Drainage Paper 56, Rome, FAO. Also available (October 2005) at www.fao.org/docrep/X0490E/x0490e00.htm#Contents.
2. Differences in response of winter cereal varieties to applied nitrogen in the field. I. Some factors affecting the variability of responses between sites and seasons;Anderson;Field Crops Res.,1985
3. Anonymous, 2004 FAO WAICENT. http://www.fao.org/WAICENT/FAOINFO/AGRICULT/AGP/AGPC/doc/Counprof/Morocco/morocco.htm.
4. Plant breeding and drought in C3 cereals: what do we breed for?;Araus;Ann. Bot.,2002
5. The problem of sustainable water use in the Mediterranean and research requirements for agriculture;Araus;Ann. Appl. Biol.,2004