1. The Theory & Practice of Worm Gear Drives;Dudas,2000
2. Skew Axis Gearing;Saari,1960
3. Development of Gear Technology and Theory of Gearing;Litvin,1997
4. Dudley's Handbook of Practical Gear Design and Manufacture;Radzevich,2012
5. Evertz F, Gangireddy M, Mork B et al (2021) High torque skew axis gearing. http://www.spiroidgearing.com.