@article{DAN_1964_158_5_a7,
     author = {Ya. Ya. Sedol},
     title = {The free product of associative calculi with joined subalphabets and certain related questions},
     journal = {Doklady Akademii Nauk},
     pages = {1034--1037},
     publisher = {mathdoc},
     volume = {158},
     number = {5},
     year = {1964},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1964_158_5_a7/}
}