@article{ZNSL_1984_133_a12,
     author = {S. P. Novikov},
     title = {Algebro-topological approach to reality problems. {Real} action variables in the theory of finite-gap solutions of the {Sine-Gordon} equations},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {177--196},
     publisher = {mathdoc},
     volume = {133},
     year = {1984},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1984_133_a12/}
}