Comparison of shaft and flash smelting processes of copper production using thermo-ecological cost method / Bożena BORYCZKO, Janusz DONIZAK, Adam HOŁDA, Zygmunt KOLENDA, Jan NORWISZ // W: ECOS 2006 : proceedings of the 19\textsuperscript{th} international conference on Efficiency, Cost, Optimization, Simulation and environmental impact of energy systems : Aghia Pelagia, Crete, Greece, 12–14 July 2006, Vol. 2 / eds. Christos A. Frangopoulos, Constantine D. Rakopoulos, George Tsatsaronis. — [Athens : National Technical University], cop. 2006. — ISBN10: 960-87584-1-6. — S. 663–668. — Bibliogr. s. 668, Abstr.