1. Wang, L.C.H., Lee, T.F.: Torpor and hibernation in mammals: metabolic, physiological, and biochemical adaptations. In: Fregley, M.J., Blatteis, C.M. (eds.) Handbook of Physiology: Environmental Physiology, pp. 507–532. Oxford University Press, New York (1996)
2. Staples, J.F., Brown, J.C.L.: Mitochondrial metabolism in hibernation and daily torpor: a review. J. Comp. Physiol. B 178, 811–827 (2008)
3. Smith, H., Waltman, P.: Theory of Chemostat. Combridge University, Combridge (1995)
4. Smith, H., Waltman, P.: Perturbation of a globally stable steady state. Proc. AMS 127(2), 447–453 (1999)
5. Yang, Kuang: Delay Differential Equation with Application in Population Dynamics. Academic Press, Boston (1993)