A conjecture of Biggs concerning the resistance of a distance-regular graph. Markowsky, Greg; Koolen, Jacobus — 2010 The Electronic Journal of Combinatorics [electronic only]
On sum of powers of the Laplacian and signless Laplacian eigenvalues of graphs. Akbari, Saieed; Ghorbani, Ebrahim; Koolen, Jacobus H.; Oboudi, Mohammad Reza — 2010 The Electronic Journal of Combinatorics [electronic only]
Characterizing cell-decomposable metrics. Huber, Katharina T.; Koolen, Jacobus; Moulton, Vincent; Spillner, Andreas — 2008 The Electronic Journal of Combinatorics [electronic only]