@article{bwmeta1.element.bwnjournal-article-aav13i1p1bwm,
author = {Kalecki, M.},
title = {A simple elementary proof of $M(x)=\sum \_{n$\leq$x} $\mu$(n)=o(x)$
},
journal = {Acta Arithmetica},
volume = {12},
year = {1967},
pages = {1-7},
zbl = {0159.06104},
language = {en},
url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-aav13i1p1bwm}
}
Kalecki, M. A simple elementary proof of $M(x)=\sum _{n≤x} μ(n)=o(x)$
. Acta Arithmetica, Tome 12 (1967) pp. 1-7. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-aav13i1p1bwm/