Marshall W. Bern. Faster exact algorithms for steiner trees in planar networks. Networks, 20(1):109-120, 1990. [doi]
@article{Bern90-0, title = {Faster exact algorithms for steiner trees in planar networks}, author = {Marshall W. Bern}, year = {1990}, doi = {10.1002/net.3230200110}, url = {http://dx.doi.org/10.1002/net.3230200110}, researchr = {https://researchr.org/publication/Bern90-0}, cites = {0}, citedby = {0}, journal = {Networks}, volume = {20}, number = {1}, pages = {109-120}, }