1. Abbaspour-Gilandeh, Y., Alimardani, A., Khalilian, A., Keyhani, A., & Sadati, S. H. (2006). Energy requirement of site-specific and conventional tillage as affected by tractor speed and soil parameters. International Journal of Agriculture and Biology, 8, 499–503.
2. Badua, S. A. (2020). Control system response for seed placement accuracy on row crop planters. Kansas State University.
3. Badua, S. A., Sharda, A., Flippo, D., & Ciampitti, I. A. (2018). Real-time gauge wheel load variability of a row-crop planter during field operation. Transactions of the ASABE, 61(5), 1517–1527. https://doi.org/10.13031/trans.12511
4. Barbosa, R.N., & Overstreet, C. (2011). What is electrical conductivity. Preprint retrieved from https://www.lsuagcenter.com/Nr/Rdonlyres/E57e82a0-3b99-4dee-99b5-Cf2ad7c43aef/77101/Pub3185whatissoilelectricalconductivityhighres.Pdf
5. Brune, P. F., Ryan, B. J., Technow, F., & Myers, D. B. (2018). Relating planter downforce and soil strength. Soil and Tillage Research, 184, 243–252. https://doi.org/10.1016/j.still.2018.08.003