Lu, Feiyu, Zhengyu Liu, Shaoqing Zhang, and Yun Liu. (2015) 2015. “Strongly Coupled Data Assimilation Using Leading Averaged Coupled Covariance (LACC). Part I: Simple Model Study*”. Monthly Weather Review 143 (9): 3823–3837. doi:10.1175/MWR-D-14-00322.1.