RT Journal Article SR Electronic T1 Twins in sibships with Klinefelter's syndrome. JF Journal of Medical Genetics JO J Med Genet FD BMJ Publishing Group Ltd SP 114 OP 116 DO 10.1136/jmg.3.2.114 VO 3 IS 2 A1 Nielsen, J YR 1966 UL http://jmg.bmj.com/content/3/2/114.abstract AB