1. I. Suzuki, N. Takahashi, S. Shirato, H. Kawabe and S. Mitsuhashi, “Microbial Drug Resistance,” ed. by S. Mitsuhashi and H. Hashimoto, Tokyo Univ. Park Press, 1975, p. 463.
2. H. Kawaguchi, “Drug Action and Drug Resistance in Bacteria 2. Aminoglycoside Antibiotics,” ed. by S. Mitsuhasi, Univ. Tokyo Press, 1975, p. 45.