Dinuccio, Elio, Fabrizio Gioelli, Dalibor Cuk, Luca Rollè, and Paolo Balsari. “The Use of Co-Digested Solid Fraction As Feedstock for Biogas Plants”. Journal of Agricultural Engineering 44, no. 4 (February 28, 2014): 153-159. Accessed October 16, 2019. https://j.agroengineering.org/index.php/jae/article/view/jae.2013.208.