@article{CMJ_2007__57_1_a30,
     author = {Chen, Xue-Gang},
     title = {Vertices contained in all minimum paired-dominating sets of a tree},
     journal = {Czechoslovak Mathematical Journal},
     pages = {407--417},
     publisher = {mathdoc},
     volume = {57},
     number = {1},
     year = {2007},
     mrnumber = {2309974},
     zbl = {1174.05090},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/CMJ_2007__57_1_a30/}
}