Optimization of hydropower systems operation with a quadratic model. - S. A. Soliman; Gustav S. Christensen (Autom., 1988)

Optimal filtering of linear discrete dynamic systems based on least absolute value approximations. - Gustav S. Christensen; S. A. Soliman (Autom., 1990)

Optimal filtering for continuous linear dynamic systems based on WLAV approximations. - Gustav S. Christensen; S. A. Soliman (Autom., 1990)