@article{MZM_1984_35_6_a8,
     author = {E. S. Burgina},
     title = {A step sementic system for set theory},
     journal = {Matemati\v{c}eskie zametki},
     pages = {855--868},
     publisher = {mathdoc},
     volume = {35},
     number = {6},
     year = {1984},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_1984_35_6_a8/}
}