TY  - GEN
AU  - Penrose,Lionel S.
TI  - The biology of mental defect/ 
U1  - 157.8 PEN 
PY  - 1949///
CY  - London: 
PB  - Sidwick and Jackson Limited.
KW  - Medical genetics
KW  - Mental retardation
KW  - Human genetics
KW  - Genetics
ER  -