1. Blake GR, Gillman RD (1970) Thixotropic changes with aging of synthetic soil aggregates. Soil Sci Am Proc 34:561
2. Carnes A (1934) Soil crusts ? method of study their strength, and a method of overcoming injury to cotton stands. Agric Eng 15:167
3. Fapohunda HO (1975) Crop seedling emergence as affected by irrigation methods and soil types. Thesis. Colorado State University, Fort Collings, Colorado, USA
4. Chap. 3: Soil Crusts. Arizona Tech. Bull. 214;RO Gifford,1974
5. Hanks RJ (1960) Soil crusting and seedling emergence. Trans Int Congr Soil Sci 7 (1):340