@article{Grytczuk:2009,
author
=
"A.Grytczuk",
title
=
"On some classes of arithmetical functions on a semigroup $G\sb K$",
journal
=
"Acta Mathematica Hungarica",
volume
=
"Vol. 50",
number
=
"no 1-2",
pages
=
"3--16",
year
=
"1987",
}