Zimmermann, U. e. (1981). Linear and combinatorial optimization in ordered algebraic structures. North-Holland Pub. Co. : sole distributors for the U.S.A. and Canada, Elsevier North-Holland.

Zimmermann, U. ed. Linear and Combinatorial Optimization in Ordered Algebraic Structures. Amsterdam ; New York: North-Holland Pub. Co. : sole distributors for the U.S.A. and Canada, Elsevier North-Holland, 1981.

Zimmermann, U. ed. Linear and Combinatorial Optimization in Ordered Algebraic Structures. North-Holland Pub. Co. : sole distributors for the U.S.A. and Canada, Elsevier North-Holland, 1981.