. . . . . . . . . . . . . "Longitudinal studies" . "Longitudinal studies"@en . . "The sexual realm in long-term marriages a longitudinal study following marital partners over twenty years" . . . "The sexual realm in long-term marriages a longitudinal study following marital partners over twenty years"@en . . "The sexual realm in long-term marriages : a longitudinal study following marital partners over twenty years" . "Sexualité." . . . . "Längsschnittuntersuchung." . . "Sexualverhalten." . . "Comportement sexuel." . . "Ehe." . . "Mariage." . .