1. Uslovija metrizuemosti topologiceskih prostranstv i aksioma simetrii;Aleksandrov;Mat. Sb.,1938
2. Theory of (q1,q2)-quasimetric spaces and coincidence points;Arutyunov;Dokl. Math.,2016
3. A note on topological groups;Birkhoff;Compos. Math.,1936
4. On the equivalence of ecart and voisinage;Chittenden;Trans. Am. Math. Soc.,1917
5. General Topology;Engelking,1977