@article{IM2_1985_24_2_a4,
     author = {V. E. Korepin and S. L. Shatashvili},
     title = {A~three-instanton solution},
     journal = {Izvestiya. Mathematics },
     pages = {307--320},
     publisher = {mathdoc},
     volume = {24},
     number = {2},
     year = {1985},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/IM2_1985_24_2_a4/}
}