GUTMAN I, YEH Y-N, CHEN J-C. ON THE SUM OF ALL DISTANCES IN GRAPHS. Tamkang J. Math. [Internet]. 1994 Mar. 1 [cited 2024 Apr. 27];25(1):83-6. Available from: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/4428