Koczyk, Halina. “Analysis of Heating Maintenance Parameters Using the Matrix Method/Šildymo Parametrų Analizė, Naudojanti Matricų Metodą”. Journal of Civil Engineering and Management 2, no. 6 (June 30, 1996): 68-72. Accessed December 14, 2019. https://journals.vgtu.lt/index.php/JCEM/article/view/9542.