Desheng Wu Zijiang Yang Sandra Vela Liang Liang Simultaneous analysis of production and investment performance of Canadian life and health insurance companies using data envelopment analysis. 180-198 2007 34 Computers & OR 1 http://dx.doi.org/10.1016/j.cor.2005.05.005 db/journals/cor/cor34.html#WuYVL07