%0 Journal Article %A Chon, I. %A Lawson, J. D. %T Attainable sets and one-parameter semigroups of sets %J Glasgow mathematical journal %D 1991 %P 187-201 %V 33 %N 2 %U http://geodesic.mathdoc.fr/articles/10.1017/S0017089500008223/ %R 10.1017/S0017089500008223 %F 10_1017_S0017089500008223