1. Sexual attitudes and lifestyles;Johnson, A.M.; Wadsworth, J.; Wellings, K.; Field, J.; Bradshaw, S.,1994
2. Prevalence of risk prone sexual behaviour in the general population of Norway;Sundet, J.M.; Kvalem, I.L.; Magnus, P.; Bakketeig, L.S.
3. Population Censuses and Surveys. General household survey;Office of,1992