1. Lennette EH, Ballows A, Hausler WJ, Shadomy HJ (ed): Manual of clinical microbiology. American Society for Microbiology, Washington, DC. 1985, p. 154–175.
2. Hardie JM Oral streptococci. In: Sneath PHA, Nair NS, Sharpe ME, Holt, JG (ed.): Bergey's manual of systematic bacteriology. Volume 2. Williams and Wilkins, Baltimore, 1986, p. 1054–1063.
3. Lund E Antigenic relationship between pneumococci and non-hemolytic streptococci. Acta Pathologica Microbiologica Scandinavica 1950, 27: 110–118.
4. Lund E Diagnosis of pneumococci by the optochin and bile test. Acta Pathologica Microbiologica Scandinavica 1959, 47: 308–315.
5. Yurchah A. Austrian R Serologic and genetic relationship between pneumococci and other respiratory streptococci. Transactions of the Association of American Physicians 1966, 79: 368–375.