1. Isopaustic glasses for ultrasonic delay lines in colour television receivers and in digital applications;Zijlstra;Ultrasonics,1967
2. Netherlands patent 6 709 718, Philips Corporation 13 July 1967 (published 15 January 1969)
3. Glasses for temperature stable ultrasonic delay lines;Neuroth,1969
4. An ultrasonic study of some optical glasses;Inamura;Jap J Appl Phys,1967
5. Morey, G.W. The properties of glass, Chapter 11 (Reinhold, New York)