Frängsmyr, Tore؛ Heilbron, J.L.؛ Rider, Robin E. (1990). "The Broken Circle. The Challenge of Plenitude". The Quantifying Spirit in the 18th Century. University of California Press. ص. 60–61. مؤرشف من الأصل في 2019-02-22. اطلع عليه بتاريخ 2014-12-24.
Frängsmyr, Tore؛ Heilbron, J.L.؛ Rider, Robin E. (1990). "The Broken Circle. The Challenge of Plenitude". The Quantifying Spirit in the 18th Century. University of California Press. ص. 60–61. مؤرشف من الأصل في 2019-02-22. اطلع عليه بتاريخ 2014-12-24.