1. Alkema, H., de Berg, M.: Rectilinear Steiner trees in narrow strips. In: Proceedings of 37th International Symposium on Computational Geometry (SoCG), pp. 9:1–9:16 (2021)
2. Arora, S.: Polynomial time approximation schemes for Euclidean traveling salesman and other geometric problems. J. ACM 45(5), 753–782 (1998)
3. Bodlaender, H.L., Cygan, M., Kratsch, S., Nederlof, J.: Deterministic single exponential time algorithms for connectivity problems parameterized by treewidth. Inf. Comput. 243, 86–111 (2015)
4. Christofides, N.: Worst-case analysis of a new heuristic for the travelling salesman problem. Technical Report. Graduate School of Industrial Administration, Carnegie Mellon University (1976)
5. Cormen, T., Leiserson, C., Rivest, R., Stein, C.: Introduction to Algorithms, 3rd edn. MIT, Cambridge (2009)