@article{ZNSL_1980_103_a17,
     author = {A. I. Skopin},
     title = {Metabelian groups of exponent~9 with two generators},
     journal = {Zapiski Nauchnykh Seminarov POMI},
     pages = {124--131},
     publisher = {mathdoc},
     volume = {103},
     year = {1980},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/ZNSL_1980_103_a17/}
}