1. Furuya, Y., Yoshida, Y., Katayama, T., Yamamoto, S. and Kawamura, A. 1993. Serotype specific amplification of Rickettsia tsutsugamushi DNA by nested polymerase chain reaction. J. Clin. Microbiol., 31: 1637-1640.
2. Ohashi, N., Koyama, Y., Urakami, H., Fukuhara, M., Tamura, A., Kawamori, F., Yamamoto, S., Kasuya, S. and Yoshimura, K. 1996. Demonstration of antigenic and genotypic variation in Orientia tsutsugamushi which were isolated in Japan, and their classification into type and subtype. Microbiol. Immunol., 40: 627-638.