Moerdijk I., Ngo van Quê and G. E. Reyes (1987). Rings of smooth functions and their
localizations II. In Kueker D. W. , Lopez-Escobar E. K. G. and C. H. Smith (eds.).
Mathematical Logic and Theoretical Computer Science (Logic Year in Maryland 1985).
Lecture Notes in Pure and Applied Mathematics 106. New York: Marcel Dekker, 277-300.