Sakanushi, T., K. Yamada, Y. Ando, S. Matsuura, and J. Hu. “A Design Method for Simple Repetitive Controllers for Multiple-Input/Multiple-Output Time-Delay Plants”. ECTI Transactions on Electrical Engineering, Electronics, and Communications, vol. 10, no. 1, July 2011, pp. 48-58, doi:10.37936/ecti-eec.2012101.170457.