@article{MABA_1988_2_2_a6,
     author = {Duro R. Kurepa},
     title = {Constancy {Levels} of {Increasing} {Mappings} of {Some} {Kinds} of {Ordered} {Sets}},
     journal = {Mathematica balkanica},
     pages = {165},
     publisher = {mathdoc},
     volume = {2},
     number = {2},
     year = {1988},
     url = {http://geodesic.mathdoc.fr/item/MABA_1988_2_2_a6/}
}