RT Journal Article SR Electronic T1 A report on CF carrier frequency among men with infertility owing to congenital absence of the vas deferens. JF Journal of Medical Genetics JO J Med Genet FD BMJ Publishing Group Ltd SP 973 OP 973 DO 10.1136/jmg.30.11.973-a VO 30 IS 11 A1 C Williams A1 E S Mayall A1 R Williamson A1 A Hirsh A1 H Cookson YR 1993 UL http://jmg.bmj.com/content/30/11/973.2.abstract AB