T. KATZ, S. MACKIEWICZ, Z. RANACHOWSKI, Z. L. KOWALEWSKI, and Łukasz ANTOLIK, “Ultrasonic Detection of Transversal Cracks in Rail Heads – Theoretical Approach”, Eng. Trans., vol. 69, no. 4, pp. 437–456, Dec. 2021, doi: 10.24423/EngTrans.1695.20211220.