Schmedemann, Kai, Jan Sprafke, Michael Nelles, i Andrea Schüch. 2019. „Showcases of Industrial Symbiosis Related to Anaerobic Digestion at the Project UBIS”. Eco-Energetics: Technologies, Environment, Law and Economy 2 (czerwiec):123-28. https://doi.org/10.24426/eco-energetics.v2i2.117.