A characterization of the uncapacitated network design polytope. - Johan Hellstrand; Torbjörn Larsson; Athanasios Migdalas (Oper. Res. Lett., 1992)

Solving the Uncapacitated Network Design Problem by a Lagrangean Heuristic and Branch-and-Bound. - Kaj Holmberg; Johan Hellstrand (Oper. Res., 1998)