Copy and paste this link:
http://journals.cambridge.org/action/displayAbstract?aid=364260
Copy and paste this citation
CHRISTIAN BORGS
(2006).
Absence of Zeros for the Chromatic Polynomial on Bounded Degree Graphs. Combinatorics, Probability and Computing, 15
,
pp 63-74
doi:10.1017/S0963548305006942