S Robinson, H Syddall, K Jameson, S Batelaan, H Martin, E. M Dennison, C Cooper, A. A Sayer and The Hertfordshire Study Group
Age and Ageing 38 ( 5 ): 594 - 599 , 2009
H Syddall, H. C Roberts, C Cooper, H Bergman and A. A. Sayer
Age and Ageing 39 ( 2 ): 197 - 203 , 2010