Krichever, I. M.; Novikov, S.P. (1987). "Algebras of Virasoro type, Riemann surfaces and structures of the theory of solitons". Funkts. Anal. Appl. 21 (2): 46–63. doi:10.1007/BF01078026. S2CID55989582.
Krichever, I. M.; Novikov, S.P. (1987). "Algebras of Virasoro type, Riemann surfaces and structures of the theory of solitons". Funkts. Anal. Appl. 21 (2): 46–63. doi:10.1007/BF01078026. S2CID55989582.