Deoxyribonucleic Acid (DNA)relatedness between serogroups and serovars in the family Leptospiraceae with proposals for seven new Leptospira species - Yasuda, Paulo Hideki; Steigerwalt, Arnol G.; Sulzer, K. R.; Kaufmann, A. F.; Roger, F.; Brenner, D. J. (International Journal of Systematic Bacteriology, 1987)