B. B. Ivanov, D. S. Nikolova, E. G. Kirilova, N. G. Vaklieva-Bancheva, and R. K. Vladova, “Optimal Design of Sustainable Biodiesel Supply Chain Using Dairy Waste Scum as a Feedstock Generated from Dairy Supply Chain”, Chemical Engineering Transactions, vol. 88, pp. 577-582, Nov. 2021.