Francis Y. L. Chin, Zeyu Guo, He Sun. Minimum Manhattan network is NP-complete. In John Hershberger, Efi Fogel, editors, Proceedings of the 25th ACM Symposium on Computational Geometry, Aarhus, Denmark, June 8-10, 2009. pages 393-402, ACM, 2009. [doi]
Abstract is missing.