@article{DMGT_2012_32_3_a9,
     author = {Shahul Hameed, K. and Germina, K.},
     title = {On composition of signed graphs},
     journal = {Discussiones Mathematicae. Graph Theory},
     pages = {507--516},
     publisher = {mathdoc},
     volume = {32},
     number = {3},
     year = {2012},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/DMGT_2012_32_3_a9/}
}