POSITIVITY, cilt.7, ss.141-148, 2003 (SCI-Expanded)
Let E, F be Archimedean Riesz spaces. We consider operators that map ideals of E to ideals of F and operators T for which, T-1(I) is an ideal in E, for each ideal I in F. We study the properties of such operators and investigate their relation to disjointness preserving operators.