MYKOLA SYSYN; VITALII KOVALCHUK; ULF GERBER; OLGA NABOCHENKO; BOGDAN PARNETA. Laboratory Evaluation of Railway Ballast Consolidation by the Non-Destructive Testing. Communications - Scientific letters of the University of Zilina, v. 21, n. 2, p. 81-88, 24 May 2019.