@article{PIM2_1991__50(64)_257873,
     author = {Powell, Barry J. and \v{S}al\'at, Tibor},
     title = {Convergence of subseries of the harmonic series and asymptotic densities of sets of positive integers.},
     journal = {Publications de l 'Institut Math\'ematique. Nouvelle S\'erie},
     pages = {60},
     publisher = {mathdoc},
     volume = {50(64)},
     year = {1991},
     zbl = {0745.11008},
     language = {en},
     url = {https://geodesic-test.mathdoc.fr/item/PIM2_1991__50(64)_257873/}
}