@article{RCM_1985__19_181744,
     author = {M.W. Bunder},
     title = {Natural {Numbers} {In} {Illative} {Combinatory} {Logic.}},
     journal = {Revista colombiana de matematicas},
     pages = {31--42},
     publisher = {mathdoc},
     volume = {19},
     year = {1985},
     zbl = {0612.03012},
     url = {http://geodesic.mathdoc.fr/item/RCM_1985__19_181744/}
}