1. Segal’, M.: Errors impact on contact conditions of spatial gear. Mashinovedenie 5, 49–54 (1975). (in Russian)
2. Litvin, F.: Development of Gear Technology and Theory of Gearing, p. 124. NASA Reference Publication 1406, ARL-TR-1500 (1998)
3. Lagutin, S., Verhovski, A., Dolotov, S.: Technological design of worm gears with a localized contact. In: Proceedings of 2nd International Conference “Power Transmissions 2006”, Novi Sad, Serbia, pp. 177–182 (2006)
4. Baxter, M.: Basic geometry and tooth contact of hypoid gears. Ind. Math. 11 (Part 2), 19–42 (1961)
5. Litvin, F.: Theory of Gearing, p. 584. Nauka, Moscow (1968). (in Russian)