Vassilev, S., M. Yossifova, C. Vassileva. 1994. Mineralogy and geochemistry of Bobov Dol coals, Bulgaria.International Journal of Coal Geology, 26 (3/4): 185-214.
Vassilev, S., C. Vassileva. 1996. Occurrence, abundance and origin of minerals in coals and coal ashes. Fuel Processing Technology, 48: 85-106.
Vassilev, S., C. Vassileva. 1996. Mineralogy of combustion wastes from coal-fired power stations. Fuel Processing Technology, 47: 261-280.
Vassilev, S., K. Kitano, C. Vassileva. 1996. Some relationships between coal rank and chemical and mineral composition. Fuel, 75 (13): 1537-1542.
Vassileva, B., S. Vassilev, C. Vassileva. 1996. Effective use of mineral sorbents for purification of waste waters from thermo-electric power stations. Comptes rendus de l'Academie Bulgare des Sciences, 49 (4): 59-62.
Vassilev, S., C. Vassileva. 1997. Geochemistry of coals, coal ashes and combustion wastes from coal-fired power stations. Fuel Processing Technology, 51: 19-45.
Vassilev, S., K. Kitano, C. Vassileva. 1997. Relations between ash yield and chemical and mineral composition of coals. Fuel, 76 (1): 3-8.
Vassilev, S., C. Vassileva. 1998. Comparative chemical and mineral characterization of some Bulgarian coals. Fuel Processing Technology, 55: 55-69.
Vassilev, S., G. Eskenazy, C. Vassileva. 2000. Contents, modes of occurrence and origin of chlorine and bromine in coal. Fuel, 79: 903-921.
Vassilev, S., G. Eskenazy, C. Vassileva. 2000. Contents, modes of occurrence and behaviour of chlorine and bromine in combustion wastes from coal-fired power stations. Fuel, 79: 923-937.
Vassilev, S., G. Eskenazy, C. Vassileva. 2001. Behaviour of elements and minerals during preparation and combustion of the Pernik coal, Bulgaria. Fuel Processing Technology, 72: 103-129.
Vassileva, C., S. Vassilev. 2002. Relations between ash-fusion temperatures and chemical and mineral composition of some Bulgarian coals. Comptes rendus de l'Academie Bulgare des Sciences, Tome 55 (6): 61-66.
Vassileva, C., S. Vassilev. 2002. General observations on the phase-mineral transformations in inorganic matter of some Bulgarian coals during heating. Comptes rendus de l'Academie Bulgare des Sciences, Tome 55 (7): 47-50.
Vassileva, C. 2003. Phase-mineral transformations in inorganic matter of Bulgarian lignites during heating. -Comptes rendus de l'Academie Bulgare des Sciences, 56 (6), 41-48.
Vassileva, C. 2003. Phase-mineral transformations in inorganic matter of Bulgarian subbituminous and bituminous coals during heating. - Comptes rendus de l'Academie Bulgare des Sciences, 56 (9), 19-26.
Vassileva, C., S. Vassilev. 2004. Some environmental aspects related to sulphur emissions during combustion of Bulgarian coals. Comptes rendus de l'Academie Bulgare des Sciences, 57 (9): 29-32.
Vassileva, C. 2004. Some environmental aspects related to water-soluble fractions in Bulgarian coals and fly ashes. - Comptes rendus de l'Academie Bulgare des Sciences, 57 (7), 71-76.
Vassilev, S., C. Vassileva, A. Karayigit, Y. Bulut, A. Alastuey, X. Querol. 2005. Phase-mineral and chemical composition of composite samples from feed coals, bottom ashes and fly ashes at the Soma power station, Turkey.International Journal of Coal Geology, 61 (1-2): 35-63.
Vassilev, S., C. Vassileva, A. Karayigit, Y. Bulut, A. Alastuey, X. Querol. 2005. Phase-mineral and chemical composition of fractions separated from composite fly ashes at the Soma power station, Turkey. International Journal of Coal Geology, 61 (1-2): 65-85.
Vassilev, S., C. Vassileva. 2005. Methods for characterization of composition of fly ashes from coal-fired power stations: a critical overview. Energy and Fuels, 19 (3): 1084-1098.
Vassilev, S., C. Vassileva. 2005. Mineralogy and geochemistry of coals and their combustion and pyrolysis products. Anniversary Volume “Ten Years of CLMC-BAS”, Sofia, Marin Drinov: 33-40.
Vassileva, C., S. Vassilev. 2005. Behaviour of inorganic matter during heating of Bulgarian coals. 1. Lignites. Fuel Processing Technology, 86 (12-13): 1297-1333.
Karayigit, A., Y. Bulut, G. Karayigit, X. Querol, A. Alastuey, S. Vassilev, C. Vassileva. 2006. Mass balance of major and trace elements in a coal-fired power plant. Energy Sources, 28: 1311-1320.
Vassilev, S.,N. Lihareva, C. Vassileva. 2006. Sequential leaching behaviour of some elements during chemical treatment of Bobov Dol coal fly ash. Comptes rendus de l'Academie Bulgare des Sciences, 59 (6): 645-650.
Vassilev, S.,N. Lihareva, C. Vassileva. 2006. Sequential leaching behaviour of some elements during chemical treatment of ceramic cenospheres from coal fly ash. - Comptes rendus de l'Academie Bulgare des Sciences, 59 (7): 753-758.
Vassileva, C., S. Vassilev. 2006. Behaviour of inorganic matter during heating of Bulgarian coals. 2. Subbituminous and bituminous coals. Fuel Processing Technology, 87: 1095-1116.
Vassilev, S., C. Vassileva. 2007. A new approach for the classification of coal fly ashes based on their origin, composition, properties, and behaviour. Fuel, 86: 1490-1512.
Vassilev, S., C. Vassileva. 2009. A new approach for the combined chemical and mineral classification of the inorganic matter in coal. 1. Chemical and mineral classification systems. Fuel, 88: 235-245.
Vassilev, S., C. Vassileva, D. Baxter, L. Andersen. 2009. A new approach for the combined chemical and mineral classification of the inorganic matter in coal. 2. Potential applications of the classification systems. Fuel, 88: 246-254.