@article{DMGT_2006_26_2_a2,
     author = {Poschen, Michael and Volkmann, Lutz},
     title = {A lower bound for the irredundance number of trees},
     journal = {Discussiones Mathematicae. Graph Theory},
     pages = {209--215},
     publisher = {mathdoc},
     volume = {26},
     number = {2},
     year = {2006},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/DMGT_2006_26_2_a2/}
}