@article{RO_2003__37_3_179_0,
     author = {Chen, Guangting and Burkard, Rainer E.},
     title = {Constrained {Steiner} trees in {Halin} graphs},
     journal = {RAIRO - Operations Research - Recherche Op\'erationnelle},
     pages = {179--194},
     publisher = {EDP-Sciences},
     volume = {37},
     number = {3},
     year = {2003},
     doi = {10.1051/ro:2003020},
     mrnumber = {2034538},
     zbl = {1039.05058},
     language = {en},
     url = {http://www.numdam.org/articles/10.1051/ro:2003020/}
}