@article{DMGT_2011_31_3_a7,
     author = {Fricke, Gerd and Hedetniemi, Sandra and Hedetniemi, Stephen and Hutson, Kevin},
     title = {\ensuremath{\gamma}-graphs of graphs},
     journal = {Discussiones Mathematicae. Graph Theory},
     pages = {517--531},
     publisher = {mathdoc},
     volume = {31},
     number = {3},
     year = {2011},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/DMGT_2011_31_3_a7/}
}