RT Journal Article SR Electronic T1 Mental retardation in a child with a long B-group chromosome. JF Journal of Medical Genetics JO J Med Genet FD BMJ Publishing Group Ltd SP 134 OP 136 DO 10.1136/jmg.5.2.134 VO 5 IS 2 A1 Tischler, B A1 Corey, M J A1 Co-Te, P YR 1968 UL http://jmg.bmj.com/content/5/2/134.abstract AB