The rectilinear steiner arborescence problem

F. R. K. Chung and R. L. Graham, On Steiner trees for bounded sets,Geom. Dedicata 11 (1981), 353–361.

L. Few, The shortest path and shortest roads throughn points,Mathematika 2 (1955), 141–144.

M. R. Garey and D. S. Johnson, The rectilinear Steiner tree problem is NP-complete,SIAM J, Appl. Math. 32 (1977), 826–834.

M. Hanan, On Steiner's problem with rectilinear distance,SIAM J. Appl. Math. 14 (1966), 255–265.

F. K. Hwang, On Steiner minimal trees with rectilinear distance,SIAM J. Appl. Math. 30 (1976), 104–114.

F. K. Hwang, AnO(n logn) algorithm for rectilinear minimal spanning trees,J. Assoc. Comput. Mach. 26 (1979), 177–182.

R. R. Ladeira de Matos, A Rectilinear Arborescence Problem, Dissertation, University of Alabama, 1979.

L. Nastansky, S. M. Selkow, and N. F. Stewart, Cost-minimal trees in directed acyclic graphs,Z. Oper. Res. 18 (1974), 59–67.

J. S. Provan, A Polynomial Algorithm for the Steiner Tree Problem on Terminal-Planar Graphs, Technical Report UNC/ORST/TR-83/10, University of North Carolina, 1983.

R. E. Tarjan, Finding optimum branchings,Networks 7 (1977), 25–35.

V. A. Trubin, Subclass of the Steiner problems on a plane with rectilinear metric,Cybernetics 21 (1985), 320–322, translated fromKibernetika 21, No. 3 (1985), 37–40.