TY  - JOUR
A1  - Kallan, J.
A1  - Udry, J.R.
T1  - The determinants of effective fecundity based on the first birth interval
Y1  - 1986
DO  - 10.2307/2061407
JF  - Demography 
VL  - 23
IS  - 1
SP  - 53
EP  - -66

ER  -