[1]
A. Stockl, D. Loeffler, H. Oechsner, T. Jungbluth, K. Fischer, and M. Kranert, “Near-infrared-reflection spectroscopy as measuring method to determine the state of the process for automatic control of anaerobic digestion”, Int J Agric & Biol Eng, vol. 6, no. 2, pp. 63–72, Jun. 2013.