APA

Vereinte Nationen, . (1993). Studies in methods / United Nations, Department of Economic and Social Affairs, Statistics Division. New York, NY: United Nations.

Chicago

Vereinte Nationen, . 1993. Studies in methods / United Nations, Department of Economic and Social Affairs, Statistics Division. New York, NY: United Nations.

Harvard

Vereinte Nationen, . (1993). Studies in methods / United Nations, Department of Economic and Social Affairs, Statistics Division. New York, NY: United Nations.

MLA

Vereinte Nationen, . Studies in methods / United Nations, Department of Economic and Social Affairs, Statistics Division. New York, NY: United Nations. 1993.