Chalupczak, J., and T. Milek. “Comparison of Simulation and Experimental Axial Loadings for Hydromechanical Bulge Forming of Copper Cross-Joints”. Communications - Scientific Letters of the University of Zilina, Vol. 7, no. 4, Dec. 2005, pp. 14-17, http://journals.uniza.sk/index.php/communications/article/view/1260.