Second order SSP ARK IMEX scheme. This method has three implicit stages.
References
1. -L. Pareschi, G. Russo, Implicit Explicit Runge Kutta schemes and applications to hyperbolic systems with relaxations. Journal of Scientific Computing Volume: 25, Issue: 1, October, 2005.
This method is referred to as SSP2-(3,3,2) in http://arxiv.org/abs/1110.4375