In the original article ``Wiener index of Eulerian graphs'' [Discrete Applied
Mathematics Volume 162, 10 January 2014, Pages 247-250], the authors state that
the Wiener index (total distance) of an Eulerian graph is maximized by the
cycle. We explain that the initial proof contains a flaw and note that it is a
corollary of a result by Plesn\'ik, since an Eulerian graph is
2-edge-connected. The same incorrect proof is used in two referencing papers,
``Zagreb Indices and Multiplicative Zagreb Indices of Eulerian Graphs'' [Bull.
Malays. Math. Sci. Soc. (2019) 42:67-78] and ``Harary index of Eulerian
graphs'' [J. Math. Chem., 59(5):1378-1394, 2021]. We give proofs of the main
results of those papers and the 2-edge-connected analogues.Comment: 5 Pages, 1 Figure Corrigendum of 3 papers, whose titles are combine