Spatial economics : density, potential, and flow /
Martin Beckmann, Tönu Puu.
- Amsterdam ; New York : New York, N.Y., U.S.A. : North-Holland ; Sole distributors for the U.S.A. and Canada, Elsevier Science Pub. Co., 1985.
- xii, 276 p. : ill. ; 25 cm.
- Studies in regional science and urban economics ; v. 14 .