1) Ikeda, T., et al.: Prevalence of Streptococcus mutans on various tooth surface s in negro children, Archs. oral Biol., 16: 1237- 1240, 1971.
2) Ikeda, T., et al.: Changes in Streptococcus mutans and lactobacilli in plaque in relation to the initiation of dental caries in negro children, Archs. oral Biol., 18: 555-566, 1973.
3) Loesche, W. J., et al.: The predominant cultivable flora of carious plaque and carious dentine, Caries Res., 7: 201-216, 1973.
4) Challacombe, S. J., et al.: Serum an d salivary antibodies to cariogenic bacteria in man, J. Dent. Res., 55: c139-c148, 1976.
5) Mestecky, J., et al.: S elective induction of an immune response in human external secretio n by ingestion of bacterial antigen, J. Clin. Invest., 61: 731-737, 1978.