@article{10_4153_CMB_1981_014_7,
     author = {Donnelly, Harold},
     title = {On {L2-Betti} {Numbers} for {Abelian} {Groups}},
     journal = {Canadian mathematical bulletin},
     pages = {91--95},
     year = {1981},
     volume = {24},
     number = {1},
     doi = {10.4153/CMB-1981-014-7},
     url = {http://geodesic.mathdoc.fr/articles/10.4153/CMB-1981-014-7/}
}