1. Characterizations of absolute $F_{\sigma\delta}$-sets Creator: Junnila, Heikki J. K. and Künzi, Hans-Peter A. Format: bez média and svazek Type: model:article and TEXT Subject: metric space, $F_{\sigma \delta }$-set, bicomplete quasi-metric, complete sequence of covers, compact family of sets, and cotopology Language: English Rights: http://creativecommons.org/publicdomain/mark/1.0/ and policy:public