Intrinsic current-voltage properties of nanowires with four-probe scanning tunneling microscopy: A conductance transition of ZnO nanowire - X. Lin; X.B. He; T.Z. Yang; W. Guo; D.X. Shi; H.-J. Gao; D.D.D. Ma; S.T. Lee; F. Liu; X.C. Xie (Applied Physics Letters, 2006)