TY - JOUR A1 - Timæus, I.M. A1 - Moultrie, T.A. T1 - Distinguishing the impact of postponement, spacing and stopping on birth intervals: Evidence from a model with heterogeneous fecundity Y1 - 2013 DO - 10.1017/S0021932012000648 JF - Journal of Biosocial Science VL - 45 IS - 3 ER -