A sensitive umu test system for the detection of mutagenic nitroarenes in Salmonella typhimurium NM1011 having a high nitroreductase activity - Takehiko Nohmi; Masahiko Watanabe; Motoi Ishidate; Yoshimitsu Oda; Tsutomu Shimada (Mutation Research/Environmental Mutagenesis and Related Subjects, 1992)