TY  - BOOK
AU  - Beck, Robert Clarence.
TI  - Motivation: theories and principles 
SN  - 0136039022 
PY  - 1978///
CY  - Englewood Cliffs, N.J.
PB  - Prentice-Hall
KW  - Motivation (Psychology)
N1  - Includes indexes; Bibliography: p. 419-459
ER  -