@article{MZ_1970__113_171264,
     author = {Choon Jai Rhee},
     title = {Homotopy {Functors} {Determined} by {Set-Valued} {Maps.}},
     journal = {Mathematische Zeitschrift},
     pages = {154--158},
     publisher = {mathdoc},
     volume = {113},
     year = {1970},
     zbl = {0183.28001},
     url = {http://geodesic.mathdoc.fr/item/MZ_1970__113_171264/}
}