@article{PORMA_1968__27_3_115071,
     author = {Lai, Hon-Fei},
     title = {On piecewise-constant functions},
     journal = {Portugaliae mathematica},
     pages = {161--168},
     publisher = {mathdoc},
     volume = {27},
     number = {3},
     year = {1968},
     mrnumber = {0270347},
     zbl = {0198.27301},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/PORMA_1968__27_3_115071/}
}