TY - JOUR A1 - Brown, S.L. A1 - Manning, W.D. T1 - Family Boundary Ambiguity and the Measurement of Family Structure: The Significance of Cohabitation Y1 - 2009 DO - 10.1353/dem.0.0043 JF - Demography VL - 46 IS - 1 SP - 85 EP - -101 ER -