@article {10001,
	title = {Gate-tunable exchange coupling between cobalt clusters on graphene},
	journal = {Physical Review B - Condensed Matter and Materials Physics},
	year = {2013},
	doi = {10.1103/PhysRevB.87.144410},
	author = {Hua Chen and Qian Niu and Zhenyu Zhang and Allan H. MacDonald}
}
