On the Embedding of topological domains into quotient fields. John K. Luedeman — 1970 Manuscripta mathematica
Closure operations and semigroups of quotients John K. Luedeman — 1979 Commentationes Mathematicae Universitatis Carolinae
Quasi-injective S -systems and their S -endomorphism semigroup Antonio M. Lopez, Jr.; John K. Luedeman — 1979 Czechoslovak Mathematical Journal
Semigroups for which every totally irreducible S -system is injective John K. Luedeman; Frederick R. McMorris; Soon Kiong Sim — 1978 Commentationes Mathematicae Universitatis Carolinae