참고문헌
- Geometry Ⅰ M. Berger
- Trans. Amer. Math. Soc. v.274 Polynomials on affine manifolds D. Fried
- Trans. Amer. Math. Soc. v.286 The Radiance Obstruction and Parallel Forms on Affine Manifolds W. Goldman;M. Hirsch
- Lecture Notes in Mathematics v.67 Flat manifolds F. Kamber;P. Tondeur
- Comm. Math. Helv. v.32 On the existence of a connection with curvature zero John Milnor