On the Uncapacitated Plant Location Problem. I: Valid Inequalities and Facets. - D. Chinhyung Cho; Ellis L. Johnson; Manfred Padberg; M. R. Rao (Math. Oper. Res., 1983)

On the Uncapacitated Plant Location Problem. II: Facets and Lifting Theorems. - D. Chinhyung Cho; Manfred W. Padberg; M. R. Rao (Math. Oper. Res., 1983)