↑ Atiyah 2007, p. 1 harvnb error: no target: CITEREFAtiyah2007 (help) ↑ Kostrikin 2001, This quote is the first sentence of the final section named comments in this single-paged-document harvnb error: no target: CITEREFKostrikin2001 (help) ↑ Gowers 2008, p. 187, col. 1 ↑ Gowers 2008, p. 189, col. 2 ↑ Atiyah 2007, p. 1 harvnb error: no target: CITEREFAtiyah2007 (help) ↑ The complement is also denoted as S \ A. ↑ More precisely, C ∗ ∗ {\displaystyle C^{**}} is the smallest closed convex cone containing C {\displaystyle C} . ↑ Artstein-Avidan & Milman 2007 ↑ Artstein-Avidan & Milman 2008 ↑ Veblen & Young 1965. ↑ (Veblen & Young 1965, Ch. I, Theorem 11) ↑ More generally, one can consider the projective planes over any field, such as the complex numbers or finite fields or even division rings. ↑ See elliptic regularity. ↑ Edwards (1965, 8.4.7). ↑ Fulton 1993 ↑ Mac Lane 1998, Ch. II.1. ↑ (Lam 1999, §19C) ↑ Jiří Adámek; J. Rosicky (1994).