食品和动物饲料的微生物学-蜡样芽孢杆菌推定计数的水平方法-30℃菌落计数法-修正案1:增加可选试验Microbiology of food and animal feeding stuffs - Horizontal method for the enumeration of presumptive Bacillus cereus - Colony-count technique at 30 degrees C - Amendment 1: Inclusion of optional tests