%0 Journal Article
%A Kala, V.
%A Kepka, Tomáš
%A Phillips, J. D.
%T Various subsemirings of the field $\Bbb Q$ of rational numbers
%J Acta Universitatis Carolinae. Mathematica et Physica
%D 2009
%P 29-59
%V 50
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/AUCMP_2009__50_1_a3/
%G en
%F AUCMP_2009__50_1_a3