1. Benton Jones, J., Jr., Wolf, B., & Mills, H. (1991). Plant analysis handbook: A practical sampling, preparation, analysis, and interpretation guide. Athens, GA: Micro–Macro Publishing, Inc.
2. Bouyoukos, G. H. (1951). A recalibration of the hydrometer method for making mechanical analysis of soils. Agronomy Journal, 43, 434–438.
3. Bryson, M. B., Mills, H. A., Sassevile, D. N., Jones, J. B., Jr., & Barkere, A. V. (2014). Plant analysis handbook III. A guide to sampling, preparation, analysis and interpretation for agronomic and horticultural crops. Athens, GA: Micro–Macro Publishing, Inc.
4. Cao, Q., Miao, Y., Feng, G., Gao, X., Li, F., Liu, B., et al. (2015). Active canopy sensing of winter wheat canopy structure: An evaluation of two sensor systems. Computers and Electronics in Agriculture, 112, 54–67.
5. Farquhar, G. D., Ehleringer, J. R., & Hubick, K. T. (1989). Carbon discrimination and photosynthesis. Annual Review of Plant Physiology, 40, 503–537.