@article{BUMI_2002_8_5B_2_a7,
     author = {De Mari, Filippo and Nowak, Krzysztof},
     title = {Canonical subgroups of $\mathbb{H}_1\rtimes SL(2,\mathbb{R})$},
     journal = {Bollettino della Unione matematica italiana},
     pages = {405--430},
     publisher = {mathdoc},
     volume = {Ser. 8, 5B},
     number = {2},
     year = {2002},
     zbl = {1098.22007},
     mrnumber = {983366},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/BUMI_2002_8_5B_2_a7/}
}