@article{ELA_2010__20__a40,
     author = {Arav, Marina and Hall, Frank and Li, Zhongshan and Kaphle, Krishna and Manzagol, Nilay},
     title = {Spectrally arbitrary tree sign patterns of order 4},
     journal = {The electronic journal of linear algebra},
     pages = {180--197},
     publisher = {mathdoc},
     volume = {20},
     year = {2010},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/ELA_2010__20__a40/}
}