CHINESE JOURNAL OF PERINATAL MEDICINE, Volume 3, Issue 4,2000, Pages 199-201, doi:10.3760/cma.j.issn.1007-9408.2000.04.002
CHINESE JOURNAL OF PERINATAL MEDICINE, Volume 3, Issue 4,2000, Pages 231-234, doi:10.3760/cma.j.issn.1007-9408.2000.04.012
CHINESE JOURNAL OF PERINATAL MEDICINE, Volume 3, Issue 4,2000, Pages 243, doi:10.3760/cma.j.issn.1007-9408.2000.04.019