@article{MZM_2000_67_4_a11,
     author = {V. Yu. Popov},
     title = {Undecidability of the word problem in relatively free rings},
     journal = {Matemati\v{c}eskie zametki},
     pages = {582--594},
     publisher = {mathdoc},
     volume = {67},
     number = {4},
     year = {2000},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2000_67_4_a11/}
}