Hartshorne, Robin (1977), Algebraic Geometry, Graduate Texts in Mathematics, vol. 52, New York: Springer-Verlag, ISBN 978-0-387-90244-9, MR 0463157, Ch. III, Exercise 8.3}} 978-0-387-90244-9 ↩
Vakil, Ravi (2007–2008), Foundations of algebraic geometry class 38 (PDF), Stanford University http://math.stanford.edu/~vakil/0708-216/216class38.pdf ↩