TY - JOUR A1 - Eijkemans, M.J. A1 - Van Poppel, F. A1 - Habbema, D.F. A1 - Smith, K.R. A1 - Leridon, H. A1 - Te Velde, E.R. T1 - Too old to have children? Lessons from natural fertility populations Y1 - 2014 DO - 10.1093/humrep/deu056 VL - 29 IS - 6 ER -