Гутак, О. В. 2010. “ANALYSIS OF MULTICOLINEARITY OF CRITERIA OF OPTIMALITY OF PROCESS OF THE BORING DRILLING OF OIL AND GAS MINING HOLES THE CHISELS OF TYPE OF PDC”. Oil and Gas Power Engineering, no. 1(12) (March):98-101. https://nge.nung.edu.ua/index.php/nge/article/view/120.