On dichromatic polynomials

Hall, 1965, The Chromatic Polynomial of the Truncated Icosahedron, 16, 620

Harary, 1959, An Elementary Theorem on Graphs, Amer. Math. Monthly, 66, 405, 10.2307/2308754

Tutte, 1947, A Ring in Graph Theory, 43, 26

Tutte, 1954, A Contribution to the Theory of Chromatic Polynomials, Can. J. Math., 6, 80, 10.4153/CJM-1954-010-9

Whitney, 1932, A Logical Expansion in Mathematics, Bull. Amer. Math. Soc., 38, 572, 10.1090/S0002-9904-1932-05460-X