1. Arnol’d, V.I., Dopolnitel’nye glavy teorii obyknovennykh differentsial’nykh uravnenii (Additional Chapters of Ordinary Differential Equations), Moscow: Nauka, 1978.
2. Chebotarev, N.G., Teoriya algebraicheskikh funktsii (Theory of Algebraic Functions), Moscow: OGIZGITTL, 1948.
3. Chebotarev, N.G., Teoriya Galua (Galois Theory), Moscow: Knizhnyi dom Librokom, 2009.
4. Coble, A.B., An application of Moore’s cross-ratio group to the solution of the sextic equation, Trans. Am. Math. Soc., 1911, vol. 12, pp. 311–325.
5. Ince, E.L., Ordinary Differential Equations, New York: Dover, 1926; Kharkov: ONTI, 1939.