Son, Jang Won
Lee, Seong Su
Kim, Sung Rae
Yoo, Soon Jib
Cha, Bong Yun
Son, Ho Young
Cho, Nam H.
Funding for this research was provided by:
the Korea Centers for Disease Control and Prevention (2001-347-6111-221, 2002-347-6111-221, 2003-347-611)