TY - JOUR A1 - Seeman, T.E. A1 - Berkman, L.F. T1 - Structural characteristics of social networks and their relationship with social support in the elderly: who provides support Y1 - 1988 DO - 10.1016/0277-9536(88)90065-2 JF - Soc Sci Med VL - 26 IS - 7 ER -