@article{LJM_2005_17_a7,
     author = {V. Rechnoi},
     title = {Existence theorems for commutative diagrams},
     journal = {Lobachevskii journal of mathematics},
     pages = {213--230},
     year = {2005},
     volume = {17},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/LJM_2005_17_a7/}
}