@article {9561,
	title = {Dirac cones in two-dimensional systems: From hexagonal to square lattices},
	journal = {Physical Chemistry Chemical Physics},
	year = {2013},
	pages = {18855-18862},
	doi = {10.1039/c3cp53257g},
	url = {http://www.ncbi.nlm.nih.gov/pubmed/24084752},
	author = {Zhirong Liu and Jinying Wang and Jianlong Li}
}
