@article{700701,
     title = {Compactifications by adding a countable number of points},
     booktitle = {General topology and its relations to modern analysis and algebra IV},
     series = {GDML\_Books},
     publisher = {Society of Czechoslovak Mathematicians and Physicist},
     address = {Praha},
     year = {1977},
     pages = {168-169},
     mrnumber = {MR0461446},
     zbl = {0387.54009},
     url = {http://dml.mathdoc.fr/item/700701}
}

Hoshina, T. Compactifications by adding a countable number of points, dans General topology and its relations to modern analysis and algebra IV, GDML_Books,  (1977), pp. 168-169. http://gdmltest.u-ga.fr/item/700701/