%0 Journal Article %A M. R. Faghihi %A E. Ghorbani %A G. B. Khosrovshahi %A S. Tat %T On optimality of designs with three distinct eigenvalues %J The electronic journal of combinatorics %D 2013 %V 20 %N 2 %U http://geodesic.mathdoc.fr/articles/10.37236/2709/ %R 10.37236/2709 %F 10_37236_2709