@article{ZNSL_1972_32_a6,
     author = {V. A. Lifshits},
     title = {Metamathematical interpretation of the fan theorem},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {45--52},
     publisher = {mathdoc},
     volume = {32},
     year = {1972},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1972_32_a6/}
}