@article{04173055,
title = {Tau numbers, natural density, and Hardy and Wright's theorem 437.},
journal = {International Journal of Mathematics and Mathematical Sciences},
volume = {13},
year = {1990},
pages = {383-386},
doi = {10.1155/S0161171290000576},
zbl = {0713.11002},
language = {en},
url = {http://dml.mathdoc.fr/item/04173055}
}
Kennedy, Robert E.; Cooper, Curtis N. Tau numbers, natural density, and Hardy and Wright's theorem 437.. International Journal of Mathematics and Mathematical Sciences, Tome 13 (1990) pp. 383-386. doi : 10.1155/S0161171290000576. http://gdmltest.u-ga.fr/item/04173055/