@article{SM_2006_197_9_a3,
     author = {A. O. Ivanov and A. A. Tuzhilin},
     title = {Uniqueness of  {Steiner} minimal trees on  boundaries
},
     journal = {Sbornik. Mathematics},
     pages = {1309--1340},
     publisher = {mathdoc},
     volume = {197},
     number = {9},
     year = {2006},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/SM_2006_197_9_a3/}
}