1. Brokowski A., Deputat J. Ultrasonic Measurements of Residual Stresses in Rails. Proc. 11 WC NDT, Las Vegas, Taylor Publ. Co., Dallas, 1985, p. 596
2. Utrata D. Stress Measurements in Rails Using Ultrasonic-Based Nondestructive Methods and Strain Gage Hoi1-Drilling. Association of American Railroads, Report R-779, June 1991