Tuning of PID-type controllers for stable and unstable systems with time delay. - Z. Shafiei; Andrew Thomas Shenton (Autom., 1994)

Frequency-domain design of pid controllers for stable and unstable systems with time delay. - Z. Shafiei; Andrew Thomas Shenton (Autom., 1997)

Relative stability for open-loop stable and unstable discrete control systems with perturbed or adjustable parameters. - Z. Shafiei; Andrew Thomas Shenton (ECC, 1999)