Zimmermann, Reinhard MPI for Comparative and International Private Law, Max Planck Society;
https://max-eup2012.mpipriv.de/index.php/Mixed_Legal_Systems (Any fulltext)
Zimmermann, R. (2012). Mixed Legal Systems. In J. Basedow, K. J. Hopt, & R. Zimmermann (Eds.), The Max Planck Encyclopedia of European Private Law (pp. 1179-1182). Oxford: Oxford University Press.