Prussia, Called Frederick the Great (英語). Vol. VI. London: Chapman & Hall. OCLC 1045538020。 Clark, Christopher (2006). Iron Kingdom: The Rise and Downfall
Scientific Units - Including dimensionless numbers and scales (6 ed.). London: Chapman and Hall. p. 100. ISBN 0412467208. OCLC 803100353. OL OL1351307M ^ Cardarelli
Called Frederick the Great (英語). Vol. III. London: Chapman & Hall(英語版). OCLC 1045538020。 Clark, Christopher (2006). Iron Kingdom: The Rise and Downfall