Pisanski, Tomaž; Randić, Milan (2000), "Bridges between geometry and graph theory", in Gorini, Catherine A. (ed.), Geometry at work, MAA Notes, vol.53, Washington, DC: Math. Assoc. America, pp.174–194, MR1782654. See in particular Theorem3, p.176.
Pisanski, Tomaž; Randić, Milan (2000), "Bridges between geometry and graph theory", in Gorini, Catherine A. (ed.), Geometry at work, MAA Notes, vol.53, Washington, DC: Math. Assoc. America, pp.174–194, MR1782654. See in particular Theorem3, p.176.