RT Journal Article SR Electronic T1 Human Multiple Reproduction JF Journal of Medical Genetics JO J Med Genet FD BMJ Publishing Group Ltd SP 154 OP 154 DO 10.1136/jmg.14.2.154-a VO 14 IS 2 A1 M. G. Bulmer YR 1977 UL http://jmg.bmj.com/content/14/2/154.2.abstract AB