Columbia subject headings:
Birth control--Norway--Mathematical models.
Family size--Norway--Mathematical models.
Fertility, Human--Economic aspects--Norway.
Fertility, Human--Norway--Mathematical models.
Harvard subject headings:
Birth control--Norway--Mathematical models.
Family size--Norway--Mathematical models.
Fertility, Human--Economic aspects--Norway.
Fertility, Human--Norway--Mathematical models.
Princeton subject headings:
Contraception--Mathematical models.
Contraception--Norway.
Fertility, Human--Mathematical models.
Fertility, Human--Norway.