@article{AL_1966_5_6_a2,
     author = {V. M. Kopytov},
     title = {On the theory of preorderable groups},
     journal = {Algebra i logika},
     pages = {27--31},
     publisher = {mathdoc},
     volume = {5},
     number = {6},
     year = {1966},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1966_5_6_a2/}
}