1. PINDERA, J.T., HECKER, F.W. and KRASNOWSKI, B.R., “Gradient Photoelasticity”, Mechanics Research Communications, Vol. 9, 1982, pp. 197–204.
2. BOKSTHEIN, M.F., “On the Resolving Power of the Polarizing System for Stress Investigations”, (in Russian), Zhurnal Tekhnicheskoi Fiziki, Vol. 19, 1949, pp. 1103–1106.
3. PINDERA, J.T., “Technique of Photoelastic Investigations of Plane Stress States”, (in Polish), Rozprawy Inzynierskie, Vol. 3, 1955, pp. 109–176.
4. POST, D., “Optical Analysis of Photoelastic Polariscopes”, Experimental Mechanics, Vol. 10, 1970, pp. 15–23.
5. HECKER, F.W., “On the Accuracy of Photoelastic Investigations of Plane Stress States with High Stress Gradients”, (in German), VDI-Berichte Nr. 480, 1983, pp. 43–49.