@article{DAN_1983_273_4_a6,
     author = {V. L. Levin},
     title = {Continuous utility theorem for closed preorders on a metrizable $\sigma$-compact space},
     journal = {Doklady Akademii Nauk},
     pages = {800--804},
     publisher = {mathdoc},
     volume = {273},
     number = {4},
     year = {1983},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1983_273_4_a6/}
}