VaR and ES for linear portfolios with mixture of elliptic distributed   Risk Factors
  In this paper, we generalize the parametric Delta-VaR methods from portfolios with elliptic distributed risk factors to portfolios with mixture of elliptically distributed ones. We treat both the Expected Shortfall and the Value-at-Risk of such portfolios. Special attention is given to the particular case of the mixture of Student-t distributions. 
Jules Sadefo Kamdem