TY  - BOOK
AU  - Helmstadter,G.C.
TI  - Research concepts in human behavior: education, psychology, sociology 
AV  - H62 H4.7
PY  - 1970///
CY  - New York
PB  - Appleton-Century-Crafts
KW  - Ciencias sociales
KW  - Investigación
ER  -