"Official Problem Set for Statistical検定 Level 2: Officially Certified by the Japan Statistical Society, 2012-2014" "Official Problem Set for Statistical検定 Level 2: Officially Certified by the Japan Statistical Society, 2016-2018" Set of two books. They show a fair amount of use. There are some writings that do not hinder solving the problems. #JapanStatisticalSociety #Books #Nature/General"