P.-St, A. “De Forenede Staters Census-Arbejder. Publications of the American Statistical Association. Boston, 1888. New Series Nos. 1, 2. 3”. Nationaløkonomisk tidsskrift 7 (January 1, 1889). Accessed December 5, 2025. https://tidsskrift.dk/nationaloekonomisktidsskrift/article/view/65437.