libraries = filter isLibrary cs
libraryGrp = filter (not . isLibrary) cs
libraries + concatMap (recurse t) libraryGrp
isLibrary r = isInstanceOf r DOCUMENT.DocumentLibrary
documents :: Model -> <ReadGraph> [Resource]
libraries = filter isLibrary cs
libraryGrp = filter (not . isLibrary) cs
libraries + concatMap (recurse t) libraryGrp
isLibrary r = isInstanceOf r DOCUMENT.DocumentLibrary
documents :: Model -> <ReadGraph> [Resource]