@article{1102905348, author = {Dickman, R. F. and Porter, Jack R.}, title = {$\theta$-closed subsets of Hausdorff spaces.}, journal = {Pacific J. Math.}, volume = {61}, number = {2}, year = {1975}, pages = { 407-415}, language = {en}, url = {http://dml.mathdoc.fr/item/1102905348} }
Dickman, R. F.; Porter, Jack R. $\theta$-closed subsets of Hausdorff spaces.. Pacific J. Math., Tome 61 (1975) no. 2, pp. 407-415. http://gdmltest.u-ga.fr/item/1102905348/