µSR Literature Entry # 2328 :

J.E. Sonier, J.H. Brewer, R.F.Kiefl, R.I.Miller, G.D. Morris, C.E. Stronach, J.S. Gardner, S.R. Dunsiger, D.A. Bonn, W.N. Hardy, R. Liang and R.H. Heffner, ``Anomalous Weak Magnetism in Superconducting YBa$_2$Cu$_3$O$_{6+x}$'', Science 292, 1692-1695 (2001).