TY  - BOOK
AU  - Smith,T.Lynn
AU  - Zopf,Paul E.
TI  - Demography : : principles and methods 
SN  - 0882840339
U1  - 304.6 23
PY  - 1976///
CY  - Philadelphia
PB  - Alfred Publishing co.
KW  - Demography
N1  - Includes bibliographical reference and index
ER  -