1. Alexandroff, P.S. (1960) On the metrization of topological spaces, Bull. Acad. Pol. Sci. Ser. Math. 8, 135–140.
2. Arens, R. and Dugundji, J. (1950) Remarks on the concept of compactness, Portugalie Math. 9, 141–143.
3. Arhangel’skii, A.V. (1962) On mappings of metric spaces, Dokl. Akad. Nauk. SSSR
145, 245–247
4. Arhangel’skii, A.V. (1962) On mappings of metric spaces, Soviet Math. Dokl. 3, 953–956.
5. Balogh, Z. (1991) On collectionwise normality of locally compact, normal spaces, Transactions AMS
323, 389–411.