1. Bierhuizen, J. F., Plant growth and soil moisture relationships. UNESCO Arid Zone Research16, 309–315 (1961).
2. Cullen, P. W., Effects of Irrigation on the Roots of Pastures M. Agr. Sc. Thesis. Univ. of Melbourne (1969).
3. Danielson, R. E., Root systems in relation to irrigationin Irrigation of Agricultural Lands. Am. Soc. Agron. MonographII (1967).
4. Hagan, R. M., Haise, H. R. and Edminster, T. W., Irrigation of Agricultural Lands. Am. Soc. Agron. MonographII (1967).
5. Israelsen, O. W. and Hansen, V. E., Irrigation Principles and Practices. Wiley, New York (1962).