The circle is the unit-diameter circle centered at with polar equation the degree-2 clover under the definition from Cox & Shurman (2005). This is not the unit-radius circle centered at the origin. Notice that the lemniscate is the degree-4 clover. Cox, David Archibald; Shurman, Jerry (2005). "Geometry and number theory on clovers"(PDF). The American Mathematical Monthly. 112 (8): 682–704. doi:10.1080/00029890.2005.11920241.
Ayoub (1984); Prasolov & Solovyev (1997)Ayoub, Raymond (1984). "The Lemniscate and Fagnano's Contributions to Elliptic Integrals". Archive for History of Exact Sciences. 29 (2): 131–149. doi:10.1007/BF00348244. Prasolov, Viktor; Solovyev, Yuri (1997). "4. Abel's Theorem on Division of Lemniscate". Elliptic functions and elliptic integrals. Translations of Mathematical Monographs. Vol. 170. American Mathematical Society. doi:10.1090/mmono/170. ISBN978-0-8218-0587-9.
Gómez-Molleda & Lario (2019) Gómez-Molleda, M. A.; Lario, Joan-C. (2019). "Ruler and Compass Constructions of the Equilateral Triangle and Pentagon in the Lemniscate Curve". The Mathematical Intelligencer. 41 (4): 17–21. doi:10.1007/s00283-019-09892-w.
Katz, Nicholas M. (1975). "The congruences of Clausen — von Staudt and Kummer for Bernoulli-Hurwitz numbers". Mathematische Annalen. 216 (1): 1–4. doi:10.1007/BF02547966. See eq. (9)
The circle is the unit-diameter circle centered at with polar equation the degree-2 clover under the definition from Cox & Shurman (2005). This is not the unit-radius circle centered at the origin. Notice that the lemniscate is the degree-4 clover. Cox, David Archibald; Shurman, Jerry (2005). "Geometry and number theory on clovers"(PDF). The American Mathematical Monthly. 112 (8): 682–704. doi:10.1080/00029890.2005.11920241.
Gauss, C. F. (1866). Werke (Band III) (in Latin and German). Herausgegeben der Königlichen Gesellschaft der Wissenschaften zu Göttingen. p. 405; there's an error on the page: the coefficient of should be , not .