TY  - BOOK
AU  - Koch,Helen Lois
TI  - Twins and twin relations
AV  - BF723.T9 K6
U1  - 155.444 
PY  - 1966///]
CY  - Chicago
PB  - University of Chicago Press
KW  - Twins
KW  - Psychology
KW  - Local
N1  - Bibliography: p. 281-292
ER  -