@article{AM2_1978__17_136734,
     author = {W.T. Tutte},
     title = {On a pair of functional equations of combinatorial interest.},
     journal = {Aequationes mathematicae},
     pages = {121--140},
     publisher = {mathdoc},
     volume = {17},
     year = {1978},
     zbl = {0377.05025},
     url = {http://geodesic.mathdoc.fr/item/AM2_1978__17_136734/}
}