1. Lancefield, R. C.: A serological differentiation of human and other groups of haemolytic streptococci. Journal of Experimental Medicine 1933, 57: 571–595.
2. Facklam, R. R.: Streptococci and aerococci. In: Lennette, E. H., Balows, A., Hausier, W. J., Truant, J. P. (ed.): Manual of clinical microbiology. American Society for Microbiology, Washington D.C., 1980, p. 88–110.
3. Amirak, I. D., Williams, R. J., Farrell, B. C. J., Noone, P.: Experience and laboratory studies in groupingβ-haemolytic streptococci with the co-agglutination grouping method, PhadebactR Streptococcus Test. In: Facklam, R., Laurell, G., Lind, I. (ed.): Recent developments in laboratory identification techniques. Excerpta Medica, Amsterdam, 1980, p. 151–158.
4. Birch, B. R., Keaney, M. G. L., Ganguli, L. A.:Streptococcus faecalis: group D or group G. Lancet 1984, i: 856.
5. Bixler-Forell, E., Martin, W. J., Moody, M. D.: Clinical evaluation of the improved Streptex method for grouping streptococci. Diagnostic Microbiology and Infectious Disease 1984, 2: 113–118.