P. Martikainen, T. Valkonen: Mortality after death of spouse in relation to duration of bereavement in Finland. In: Journal of Epidemiology and Community Health. Vol. 50, 1996, ISSN1470-2738, S.264–268, doi:10.1136/jech.50.3.264 (online [PDF; abgerufen am 15. Februar 2012]).
P. Martikainen, T. Valkonen: Mortality after death of spouse in relation to duration of bereavement in Finland. In: Journal of Epidemiology and Community Health. Vol. 50, 1996, ISSN1470-2738, S.264–268, doi:10.1136/jech.50.3.264 (online [PDF; abgerufen am 15. Februar 2012]).
P. Martikainen, T. Valkonen: Mortality after death of spouse in relation to duration of bereavement in Finland. In: Journal of Epidemiology and Community Health. Vol. 50, 1996, ISSN1470-2738, S.264–268, doi:10.1136/jech.50.3.264 (online [PDF; abgerufen am 15. Februar 2012]).