TY - JOUR A1 - Lutz, W. A1 - Skirbekk, V. A1 - Testa, M.R. T1 - The Low Fertility Trap Hypothesis: Forces that May Lead to Further Postponement and Fewer Births in Europe Y1 - 2006 DO - 10.1553/populationyearbook2006s167 JF - Vienna Yearbook of Population Research SP - 167 EP - -192 ER -