@article{DAN_1991_317_3_a20,
     author = {V. F. Yakovlev},
     title = {A two-level representation of a functional system in a hyper-real},
     journal = {Doklady Akademii Nauk},
     pages = {600--601},
     publisher = {mathdoc},
     volume = {317},
     number = {3},
     year = {1991},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1991_317_3_a20/}
}