List of citations in Numdam for : Extremal properties of eigenvalues for a metric graph

Annales de l'Institut Fourier, Volume 55 (2005) no. 1, pp. 199-211.

Buttazzo, Giuseppe;  Ruffini, Berardo;  Velichkov, Bozhidar

ESAIM: Control, Optimisation and Calculus of Variations, Volume 20 (2014) no. 1, pp. 1-22.

Adami, Riccardo;  Cacciapuoti, Claudio;  Finco, Domenico;  Noja, Diego

Annales de l'I.H.P. Analyse non linéaire, Volume 31 (2014) no. 6, pp. 1289-1310.