Published Electricity generation and atmospheric pollution: The role of solid fuels gasification by Androutsopoulos G.P., Hatzilyberis K.S. androutsopoulos_171_178.pdf
Published Malaria situation in Bulgaria and surveillance measures (1991-2000) by Kurdova R.I., Vutchev D.I., Petrov P.P. Kurdova_153_162.pdf