1. Useftulness of chromosome catalog in delincating new svndromes;l Borgaonkar DS; C, Lacassic Y.E.Stoll;Birtli Defects,1976
2. A ring-29) chromosomc;M, Atkins L.Miller W.L.Salam;J Med Getnet,1972
3. Ring F chromosome mosaicism (46. XY.20r/46. XY) in an cpileptic child without apparent haematological disease;HG, Faed M.Morton; J, Robertson;J Med Geniet,1972
4. Ring formation of chromosomes Nos 19 and 20;CC, Uchida I.A.Lin,1972
5. Ring 2(0 chromosome in a child with seizures. minor anomalies, and retardation;DT, Stewart J.M.Cavanagh N.Hughes;Arcli Dis Child; 54: 477-9. " Herva R. Saarinen I. Lcikkonen L. The r(20) syndrome,1979