@article{700621,
     title = {On the open mapping theorem},
     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 = {[68]-69},
     mrnumber = {MR0454900},
     zbl = {0365.54003},
     url = {http://dml.mathdoc.fr/item/700621}
}

Byczkowski, T. On the open mapping theorem, dans General topology and its relations to modern analysis and algebra IV, GDML_Books,  (1977), pp. [68]-69. http://gdmltest.u-ga.fr/item/700621/