Adamchuk, V. I., Hummel, J. W., Morgan, M. T., Upadhyaya, S. K. (2004). On-the-go soil sensors for precision agriculture. Computers and Electronics in Agriculture. 44: 71–91.
Adamchuk, V. I., Hemmat, A., Mouazen, A. M. (2008). Soil compaction sensor systems – current developments. ASABE Meeting Presentations. 300(8): 1–10.
Chukwu, E., Bowers, Jr. (2005). Instantanious multiple-depth soil mechanical impedance sensing from a moving vehicle. Transections of ASAE. 48: 885-894.
Campbell, G. S., Anderson, R. Y. (1998). Evaluation of simple transmission line oscillators for soil moisture measurement. Computers and Electronics in Agriculture. 20: 31–44.
Dean, T. J., Bell, J. P., Baty, A. J. B. (1987). Soil moisture measurement by an improved capactance technique, Part I. Sensor design and performance. Journal of Hydrology. 93: 67–78.
Gaskin, G. J., Miller, J. D. (1996). Measurement of Soil Water Content Using a Simplified Impedance Measuring Technique. Journal of Agriculture Engineering Research. 63: 153–60.
Hemmat, A., Rahnama, T., Vahabi, Z. (2014). A horizontal multiple-tip penetrometer for on-the-go soil mechanical resistance and acoustic failure mode detection. Soil and Tillage Research. 138:
17–25.
Huan, Zh., Wang, H., Li, Ch., Wan, C. (2017). The soil moisture sensor based on soil dielectric property. Personal and Ubiquitous Computing. 21: 67-74.
Hummel, J. W.,Ahmad, I. S., Newman, S. C., Sudduth, K. A., Drummond, S. T. (2004). simultaneous soil moisture and cone index measurement. Transections of ASABE. 47(3): 607-618.
Ledieu, J., De Ridder, P., De Clerck, P., Dautrebande, S. (1986). A method of measuring soil moisture by time-domain reflectometry. Journal of Hydrology. 88: 319–28.
Naderi-Boldaji, M., Sharifi, A., Jamshidi, B., Younesi-alamouti, M., Minaee, S. (2011). A dielectric-based combined horizontal sensor for on-the-go measurement of soil water content and mechanical resistance. Sensors and Actuators A: Physical. 171: 131–37.
Naderi-Boldaji, M., Alimardani, R., Hemmat, A, Sharifi, A., Keyhani, A., Dolatsha, N., Keller, T. (2012). Improvement and field testing of a combined horizontal penetrometer for on-the-go measurement of soil water content and mechanical resistance. Soil and Tillage Research. 123: 1–10.
Noborio, K., Kubo, T. (2017). Evaluation a dual-frequency-phase-shift soil moisture and electrical conductivity sensor. Paddy and Water Environment. 15: 573-579.
Rahnama, T. (2012). Design, development and evaluation of a combined acoustic-force sensor for on-the-go measuring soil mechanical resistance. M. Sc. Thesis, Isfahan University of Technology, Isfahan (In Farsi).
Roth, C. H., Schulin, R., Fluher, H., Attinger, W. (1990). Calibration of time domain reflectometry for water content measurement using a composite dielectric approch. Water Resources Research. 26: 2267-2273
Singh, G., Das, B. M., Chong, M. K. (1997). Measurement of moisture content with a penetrometer. Geotechnical Testing Journal. 22 (3): 317–323.
Sun, Y., Lammers, P. S., Damerow, L. (2003). A Dual Sensor for Simultaneous Investigation of Soil Cone Index and Moisture Content. Agrartechnische Forschung 9(1): 12–16.
Sun, Y., Ma, D., Lammers, P. S., Schmittmann, O., Rose, M. (2006). On-the-go measurement of soil water content and mechanical resistance by a combined horizontal penetrometer. Soil and Tillage Research. 86: 209–17.
Vafaeiyan, M. (1995) Methods of Soil Testings (2th ed). Isfahan (In Farsi).
)
