Two-stage anaerobic digestion of industrial organic waste - potentials and bottlenecks : investigations of two-stage anaerobic digestion of organic waste from the food and paper industry - olive mill solid waste, sugar beet pressed pulp and paper mill solid waste ; Zweistufige anaerobe Fermentation von industriellen organischen Reststoffen - Potenziale und Engpässe - Stoyanova, Elitza (2017)