"Verplichtingen." . . . . "Morale." . . "Morale sociale." . . "Pflicht." . . "Norme (morale)." . . "Devoir." . . "Theorie." . . . "Obligation : a social theory" . . . . . . "Obligation a social theory"@en . . . "Obligation a social theory" . . . . . . . . . "Obligation; a social theory" . . . . "Obligation" . "Obligation : A social theory" . . . .