1A. K. Abbas and A. H. Lichtman, Basic Immunology: Functions and Disordcr of the hnmune Systern 3rd edn. (Elsevier Health Sciences Division, Philadelphia USA, 2010).
2Y. Batmani and H. Khaloozadeh, Optimal chemotherapy in cancer treatment: State- dependent Riccati equation control and extended Kalman filter, Optim. Control Appl. Meth. 34 (2012) 562-577.
3N. Bellomo, N. K. Li and P. K. Maini, On the foundations of cancer modeling: Selected topics, speculations, and perspectives, Math. Mod. Meth. Appl. Sci. 18 (2008) 593-646.
4S. Chareyron and M. Alamir, Mixed immunotherapy and chemotherapy of tmnors: Feedback design and model updating schemes, d. Thor. Biol. 258 (2009) 444-454.
5L. de Pillis, K. Fister, W. Gu, T. Head, K. Maples, T. Neal, A. Murugan and K. Kozai, Optimal control of mixed immunotherapy and chemotherapy of tumors, J. Biol. Syst. 16 (2008) 51-80.
6L. G. De Pillis, W. Gu and A. E. Radunskaya, Mixed immunotherapy and chemother- apy of tumors: Modeling, applications and biological interpretations, J. Theor. Biol. 238 (2006) 841-862.
7L. G. De Pillis and A. E. Radunskaya, A mathematical tumor model with immune resistance and drug therapy: An optimal control approach, J. Theor. Med. 3 (2001) 79-100.
8K. R. Fiste and J. C. Panetta, Optimal control applied to cell-cycle-specific cancer chemotherapy, SIAM J. Appl. Math. 60 (2000) 1059-1072.
9M. Galach, Dynamics of the tumor-immune system competition -- The effect of time delay, Int. J. Appl. Math. Comput. 13 (2003) 395406.
10A. Ghaffari and M. Khazaee, Cancer dynamics for identical twin brothers, Theor. Biol. Med. Model. 9 (2012) 1-13.