[1]J. Hawrysz и H. De Ruiter, PMI, т. 167, вып. 2, сс. 335-338, фев. 2006.

[1]J. Hawrysz and H. De Ruiter, “Smart partnership for higher education: European Mineral Masters Engineering Course”, PMI, vol. 167, no. 2, pp. 335-338, Feb. 2006.