1. Novikov, M. L., 1956, USSR Patent No. 109, 750.
2. Wildhaber, E., US Patent No. 1,601,750 issued Oct. 5, 1926, and “Gears with Circular Tooth Profile Similar to the Novikov System,” VDI Berichte, No. 47, 1961.
3. Kudrjavtsev, V. N., 1966, Epicycloidal Trains, Mashgis.
4. Winter, H., and Looman, J., 1961, “Tools for Making Helical Circular Arc Spur Gears,” VDI Berichte, No. 47.
5. Litvin, F. L., 1962, “The Investigation of the Geometric Properties of a Variety of Novikov Gearing,” The Proceedings of Leningrad Mechanical Institute, No. 24 (in Russian).