TY  - BOOK
AU  - Newman,Horatio H.
AU  - Freeman,Frank N.
AU  - Holzinger,Karl J.
TI  - Twins : :  a study of heredity and environment / 
U1  - 573.21 NEW 
PY  - 1938///
CY  - Chicago : 
PB  - The University of Chicago Press
KW  - Twins-Genetics
KW  - Human beings -- Effect of environment on
KW  - Tweelingen (biologie)
N1  - Includes index.
ER  -