000			00344nam a2200133Ia 4500
001			14888
008			170722s9999 xx 000 0 und d
245			_aContributions to extension theory of topological structures /
260			_c1969.
653			_aMathematics
653			_aTopology
700			_aFlachsmeyer, J. Etc _eeditor.
942			_cGEN
999			_c75720 _d75720