P.-St, A. 1891. “The Recent Development of American Industries. By the Class of ’91, Wharton School of Finance and Economy, University of Pennsylvania. Ogsaa under Titel: Publications of the University Pennsylvania: Wharton School Studies in Politics and Economics. Vol. 1. June 1891. No. I]. Philadelphia. (111 S.)”. Nationaløkonomisk Tidsskrift 9 (January). https://tidsskrift.dk/nationaloekonomisktidsskrift/article/view/65541.