@article{AM2_1996__52_1-2_137666,
     author = {H.B. Coonce},
     title = {Permutable functions.},
     journal = {Aequationes mathematicae},
     pages = {201--214},
     publisher = {mathdoc},
     volume = {52},
     number = {1-2},
     year = {1996},
     zbl = {0894.33006},
     url = {http://geodesic.mathdoc.fr/item/AM2_1996__52_1-2_137666/}
}