@article {9908,
	title = {Double-tip scanning tunneling microscope for surface analysis},
	journal = {Physical Review B},
	year = {1995},
	pages = {5502-5505},
	doi = {10.1103/PhysRevB.51.5502},
	author = {Q. Niu and M.C. Chang and C.K. Shih}
}
