@article{IVM_1969_3_a13,
     author = {O. V. Shimel'fenig},
     title = {Certain conditions for the extension of generalized heaps},
     journal = {Izvesti\^a vys\v{s}ih u\v{c}ebnyh zavedenij. Matematika},
     pages = {104--106},
     publisher = {mathdoc},
     number = {3},
     year = {1969},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/IVM_1969_3_a13/}
}