CHINESE JOURNAL OF EPIDEMIOLOGY, Volume 20, Issue 2,1999, Pages 98-101, doi:10.3760/j.issn:0254-6450.1999.02.010
CHINESE JOURNAL OF EPIDEMIOLOGY, Volume 20, Issue 2,1999, Pages 118-121, doi:10.3760/j.issn:0254-6450.1999.02.016
CHINESE JOURNAL OF EPIDEMIOLOGY, Volume 20, Issue 2,1999, Pages 91-94, doi:10.3760/j.issn:0254-6450.1999.02.008
CHINESE JOURNAL OF EPIDEMIOLOGY, Volume 20, Issue 2,1999, Pages 82-84, doi:10.3760/j.issn:0254-6450.1999.02.005
CHINESE JOURNAL OF EPIDEMIOLOGY, Volume 20, Issue 2,1999, Pages 101, doi:10.3760/j.issn:0254-6450.1999.02.021