@article{AL_1979_18_4_a4,
     author = {V. M. Kopytov},
     title = {Free lattice-ordered groups},
     journal = {Algebra i logika},
     pages = {426--441},
     year = {1979},
     volume = {18},
     number = {4},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/AL_1979_18_4_a4/}
}