title: Social relations in older adults: Secular trends and longitudinal changes over a 16-year follow-up.
authors.affiliation: Gerontology Research Center, PO Box 35 (Viveca), FIN-40014 University of Jyväskylä, Finland. tilyyra@sport.jyu.fi
authors.forename: Tiina-Mari
authors.initials: TM
authors.lastname: Lyyra
authors.forename: Anna-Liisa
authors.initials: AL
authors.lastname: Lyyra
authors.forename: Kirsi
authors.initials: K
authors.lastname: Lumme-Sandt
authors.forename: Pirjo
authors.initials: P
authors.lastname: Tiikkainen
authors.forename: Riitta-Liisa
authors.initials: RL
authors.lastname: Heikkinen