@article{FAA_1994_28_3_a2,
     author = {S. M. Natanzon},
     title = {Classification of {Pairs} of {Arf} {Functions} on {Orientable} and {Nonorientable} {Surfaces}},
     journal = {Funkcionalʹnyj analiz i ego prilo\v{z}eni\^a},
     pages = {35--46},
     publisher = {mathdoc},
     volume = {28},
     number = {3},
     year = {1994},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/FAA_1994_28_3_a2/}
}