@article{DAN_1967_175_6_a5,
     author = {L. L. Maksimova},
     title = {Some questions on the {Ackermann} calculus},
     journal = {Doklady Akademii Nauk},
     pages = {1222--1224},
     publisher = {mathdoc},
     volume = {175},
     number = {6},
     year = {1967},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/DAN_1967_175_6_a5/}
}