1. Abbaspour-Gilandeh, Y. 2005. Continuous Energy Mapping of Tillage Systems and Modeling of the Energy Requirements by Neural Network. PhD Dissertation. Faculty of Agriculture, University of Tehran, Karaj, Iran.
  2. Ashrafizadeh, S.R. and Kushwaha, R.L. 2006. Development of a tillage energy model using a simple tool. Presented at the 2006 CSBE/SCGAB Annual Conference, Paper No.06‑130.
  3. ASAE Standards. 2001b. ASAE EP496.2: Agricultural machinery management. American Society of Agricultural Engineers. St. Joseph, MI 49085-9659, USA.27
  4. Al-Janobi, A.A. and Al-Suhaibani, S.A. 1998. Draft of primary tillage implements in sandy loam soil. Transaction of the ASAE, 14(4): 343-348.
  5. Esehaghbeygi, A., Tabatabaeefar, A.,  Keyhani, A.R. and Raoufat, M.H. 2005. Depth and rake angle’s influence on the draft force of an oblique blade subsoiler. Iranian Journal of Agriculture Science Journal, 36 (4): 1045-1052.
  6. Godwin, R.J. and O’Dogherty, M.J. 2007 Integrated soil tillage force prediction models. Journal of Terramechanics, 44, 3-14
  7. Godwin, R.J. and Spoor, G. 1977. Soil failure with narrow tines. Journal of Agricultural Engineering Research, 22(4): 213-228.
  8. Gill, W.R. and Vandern Berg, G.E. 1968. Soil dynamics in tillage and traction. Agriculture Handbook No. 316. Agricultural Research Service, United States Department of Agriculture (USDA). pp.126-140.
  9. Grisso, R.D., Yasin, M., and Kocher, M.F. 1996. Tillage implement forces operating in silty clay loam. Transactions of the ASAE, 39(6), 1977–1982.
  10. Hettiaratchi, D.P., Witney, B.D., and Reece, A.R. 1966. The calculation of passive pressure in two dimensional soil failure. Journal of Agricultural Engineering Research, 11(2): 89-107.
  11. Kuczewski, L. and Piotrowska, E. 1998. An improved model for forces on narrow soil cutting tines. Soil and Tillage Research, 46(1998): 231-239.
  12. Manuwa, S. and Ademsun, O.C. 2007. Draught and soil disturbance of model tillage tines under varying soil parameters. Agricultural Engineering International: the CIGR Journal of Scientific Research and Development, Manuscript PM 06 016.
  13. McKyes, E. and Ali, O.S. 1977. The cutting of soil by narrow blades. Journal of Terramechanics, 14(2): 43-58.
  14. Mouazen, A.M. and Ramon, H. 2002. A numerical-statistical hybrid modeling scheme for evaluation of draught requirements of subsoiler cutting a sandy loam soil, as affected by moisture content, bulk density and depth. Soil and Tillage Research, 63:155-165.
  15. Owen, G.T. 1989. Force-depth relationships in a pedogenetically compacted clay loam soil. Applied Engineering in Agriculture, 5(2): 185-191.
  16. Perumpral, J.V., Grisso, R.D., and Desai, C.S. 1983. A soil tool model based on limit equilibrium analysis. Transactions of the ASAE, 26(4): 991-995.
  17. Upadhyaya, S.K., Williams, T.H., Kemble, L.J., and Collins, N.E. 1984. Energy requirement for chiseling in coastal plain soils. Transactions of the ASAE, 36(5): 1267-1270.