@article{10_4064_sm_101_1_19_31,
     author = {Mieczys{\l}aw K. Mentzen},
     title = {Ergodic properties of group extensions of dynamical systems with discrete spectra},
     journal = {Studia Mathematica},
     pages = {19--31},
     publisher = {mathdoc},
     volume = {101},
     number = {1},
     year = {1991},
     doi = {10.4064/sm-101-1-19-31},
     language = {en},
     url = {http://geodesic.mathdoc.fr/articles/10.4064/sm-101-1-19-31/}
}