Javier Nunez-Garcia Zoltan Kutalik Kwang-Hyun Cho Olaf Wolkenhauer Level sets and minimum volume sets of probability density functions. 25-47 2003 34 Int. J. Approx. Reasoning 1 http://dx.doi.org/10.1016/S0888-613X(03)00052-5 db/journals/ijar/ijar34.html#Nunez-GarciaKCW03