We prove that planar graphs of maximum degree 3 and of girth at least 7 are 3-edge-colorable, extending the previous result for girth at least 8 by Kronk, Radlowski, and Franen from 1974.

翻译：我们证明,最大度3和最小度7的平面图是三色的,从1974年起,Kronk、Radlowski和Franen将上个结果至少8色扩大至8色。