@article{ZNSL_2000_272_a19,
     author = {A. V. Stepanov},
     title = {Some constructions of exact sequences},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {303--320},
     publisher = {mathdoc},
     volume = {272},
     year = {2000},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_2000_272_a19/}
}