RT Journal Article SR Electronic T1 Xg groups and sex chromosome abnormalities in people of northern European ancestry: an addendum. JF Journal of Medical Genetics JO J Med Genet FD BMJ Publishing Group Ltd SP 210 OP 211 DO 10.1136/jmg.14.3.210 VO 14 IS 3 A1 Sanger, R A1 Tippett, P A1 Gavin, J A1 Teesdale, P A1 Daniels, G L YR 1977 UL http://jmg.bmj.com/content/14/3/210.abstract AB