Tree 3-Spanners on Interval, Permutation and Regular Bipartite Graphs. - M. S. Madanlal; G. Venkatesan; C. Pandu Rangan (Inf. Process. Lett., 1996)

Restrictions of Minimum Spanner Problems. - G. Venkatesan; Udi Rotics; M. S. Madanlal; Johann A. Makowsky; C. Pandu Rangan (Inf. Comput., 1997)