****************
References
****************

.. [Anderson:2007] D. F. Anderson, “A modified next reaction method for simulating chemical systems with time dependent propensities and delays.,” J. Chem. Phys., vol. 127, no. 21, p. 214107, Dec. 2007.

.. [Gillespie:1978] D. T. Gillespie, “Monte Carlo simulation of random walks with residence time dependent transition probability rates,” J. Comput. Phys., vol. 28, no. 3, pp. 395–407, Sep. 1978.

.. [Howard:1971] R. A. Howard, "Dynamic Probabilistic Systems. Vol. II:
		Semi-Markov and Decision Processes" (J. Wiley and Sons, 1971).

.. [Howard2007] R. A. Howard, Dynamic Probabilistic Systems: Semi-Markov and Decision Processes. Mineola, NY: Dover, 2007.

.. [Pyke1961] R. Pyke, “Markov Renewal Process: Definition and Preliminary Properties,” Ann. Math. Stat., vol. 32, no. 4, pp. 1231–1242, 1961.

.. [Stocks:1931] P. Stocks, "Incubation period of measles," British
		Medical Journal 1(3655): p. 157. 

.. [Viet:2004] A.-F. Viet, C. Fourichon, H. Seegers, C. Jacob,
	      and C. Guihenneuc-Jouyaux, "A model of the spread of the bovine
	      viral-diarrhoea virus within a dairy herd.," Prev. Vet. Med., vol. 63,
	      no. 3–4, pp. 211–36, May 2004.