[1] BEHREND F.:
On sequences of numbers not divisible one by another. J. London Math. Soc. 10, 1935, 42-44.
Zbl 0012.05203
[2] ERDÖS P.:
Note on sequences of integers no one of which is divisible by any other. J. London Math. Soc. 10, 1935, 126-128.
MR 1574239 |
Zbl 0012.05202
[3] OSTMANN H. H.: Additive Zahlentheorie I, II. Berlin-Gottingen-Heidelberg 1956.
[5] VOLKMANN B.:
Über Klassen von Mengen natürlicher Zahlen. J. rein. u. angew. Math. 190, 1952, 199-230.
MR 0056038