Concerning the classification of topological spaces from the stand point of the theory of retracts Karol Borsuk (1959) Fundamenta Mathematicae
Contractibility and a generalization of absolute extensor Saalfrank, C.W. (1971) Portugaliae mathematica
Convexity structures in zero-dimensional compact spaces. Kubiś, Wiesław, Kucharski, Andrzej (2001) Mathematica Pannonica
Corrections to: “Remarks on subsets of Cartesian products of metric spaces” Boris S. Klebanov (1983) Commentationes Mathematicae Universitatis Carolinae