Improved Skill for the Anomaly Correlation of Geopotential Height at 500 hPa
T.N. Krishnamurti, K. Rajendran, T.S.V. Vijaya Kumar, Stephen Lord, Zoltan Toth, Xiaolei Zou, I. Michael Navon, and Jon Ahlquist
Monthly Weather Review, 131 (2003) 1082-1102.