@article {Ko,
 AUTHOR = {Komj{\'a}th, P{\'e}ter},
 TITLE = {Ordered families of {B}aire-$2$-functions},
 JOURNAL = {Real Anal. Exchange},
 FJOURNAL = {Real Analysis Exchange},
 VOLUME = {15},
 YEAR = {1989/90},
 NUMBER = {2},
 PAGES = {442--444},
 ISSN = {0147-1937},
 MRCLASS = {26A21 (03E15 03E35)},
 MRNUMBER = {91d:26007},
 MRREVIEWER = {G. Petruska},
}
@book {Ku,
 AUTHOR = {Kuratowski, K.},
 TITLE = {Topology. {V}ol. {I}},
 PUBLISHER = {Academic Press},
 ADDRESS = {New York},
 YEAR = {1966},
 PAGES = {xx+560},
 MRCLASS = {54.00},
 MRNUMBER = {36 \#840},
 MRREVIEWER = {F. Burton Jones},
}