@article{DM_2009_21_3_a6,
     author = {A. M. Romanov},
     title = {On combinatorial {Gray} codes with distance~3},
     journal = {Diskretnaya Matematika},
     pages = {73--78},
     publisher = {mathdoc},
     volume = {21},
     number = {3},
     year = {2009},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DM_2009_21_3_a6/}
}