@article{700662,
     title = {The limit inferior of a filtered set-family as a set of limit 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 = {149-153},
     mrnumber = {MR0487945},
     zbl = {0375.54002},
     url = {http://dml.mathdoc.fr/item/700662}
}

Grimeisen, G. The limit inferior of a filtered set-family as a set of limit points, dans General topology and its relations to modern analysis and algebra IV, GDML_Books,  (1977), pp. 149-153. http://gdmltest.u-ga.fr/item/700662/