Zunzunegui, M V, Rodriguez-Laso, A, Otero, A, Pluijm, S M F, Nikula, S, Blumstein, T, Jylh�, M, Minicuci, N, Deeg, D J H & working group, C L E S A 2005, ' Disability and social ties: comparative findings of the CLESA study ', European Journal of Ageing, vol. 2, pp. 40-47 . https://doi.org/10.1007/s10433-005-0021-x European Journal of Ageing, 2, 40-47. Springer Verlag