@article{PIM_1979_N_S_26_40_a21,
     author = {{\DJ}uro Kurepa},
     title = {On {Some} {Intercalations} {In} {Ordered} {Sets}},
     journal = {Publications de l'Institut Math\'ematique},
     pages = {157 },
     publisher = {mathdoc},
     volume = {_N_S_26},
     number = {40},
     year = {1979},
     url = {http://geodesic.mathdoc.fr/item/PIM_1979_N_S_26_40_a21/}
}