@article{Romanovskii_1981,
    doi = {10.1007/bf00968275},
    url = {https://doi.org/10.1007%2Fbf00968275},
    year = {1981},
    publisher = {Springer Science and Business Media {LLC}},
    volume = {21},
    number = {2},
    pages = {273--276},
    author = {N. S. Romanovskii},
    title = {The occurrence problem for extensions of Abelian groups by nilpotent groups},
    journal = {Siberian Mathematical Journal}
}

@article{Romanovskii_1981, doi = {10.1007/bf00968275}, url = {https://doi.org/10.1007%2Fbf00968275}, year = {1981}, publisher = {Springer Science and Business Media {LLC}}, volume = {21}, number = {2}, pages = {273--276}, author = {N. S. Romanovskii}, title = {The occurrence problem for extensions of Abelian groups by nilpotent groups}, journal = {Siberian Mathematical Journal} }