[1] BOROWCZYK M., FRANKOWSKI Z., Variability of geotechnical properties of loesses in light of nowadays research methods, Geological Quarterly, 2, 23, 1979, 447-459, (in Polish).
[2] FRANKOWSKI Z., Engineering geology properties, profil Kraków-Zwierzyniec, [in:] H. Maruszczak (ed.), Elementary profiles of loesses from Poland, UMSC Committee on Quaternary Research PAN, Lublin 1991, 100-100, (in Polish).
[9] MAYNE P.W., MITCHELL J.K., AUXT J.A., YILMAZ R., U.S. National Report on CPT, International Symposium on Cone Penetration Testing, Vol. 1 (CPT’95), Swedish Geotechnical Society, Report 3, Linkőping 1995, 263-276.
[10] MŁYNAREK Z., TSCHUSCHKE W., WIERZBICKI J., Using cone penetration test and Marchetti dilatometer to evaluation of geotechnical properties of mining waste, Seminar: New methods of soil investigations, ITB, Warszawa 2003, 21-35, (in Polish).
[13] PN-EN ISO 14688-1:2006. Geotechnical investigation and testing. Identification and classification of soil. Part 1: Identification and description, PKN.