Fuzella, Tatiana, Timoshok, Evgeny (2013). PROSPECTS OF USAGE OF BIOENERGETICS AT RURAL ECONOMY OF BULGARIA. SGEM International Multidisciplinary Scientific GeoConference EXPO Proceedings; 13th SGEM GeoConference on ENERGY AND CLEAN TECHNOLOGIES, 177 - 182 pp. https://doi.org/10.5593/sgem2013/bd4/s17.023