Contractibility and a generalization of absolute extensor Saalfrank, C.W. — 1971 Portugaliae mathematica
Corrections to the article "Neighborhood retraction generalized for compact Hausdorff spaces" (Port. Math., 20(1) (1961), 11-16) Saalfrank, C.W. — 1961 Portugaliae mathematica
Neighborhood retraction generalized for compact Hausdorff spaces Saalfrank, C.W. — 1961 Portugaliae mathematica
A characterization of contractible compact Hausdorff spaces Saalfrank, C.W.; Jaworowski, J.W. — 1962 Portugaliae mathematica