RT Journal T1 New upper bound on the chromatic number of the square of a planar graph A1 ZHU Hai-yang, GU Yu, LÜ Xin-zhong PB JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE) FD 2016-02-16 YR 2016 JF JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE) JO JOURNAL OF SHANDONG UNIVERSITY(NATURAL SCIENCE) VO 51 IS 2 SP 94 DO 10.6040/j.issn.1671-9352.0.2014.594 K1 coloring;planar graph;squares;girth LK {http://lxbwk.njournal.sdu.edu.cn/EN/article/article_2814.shtml}