TITLE: Reference for flatness in complex-analytic geometry
QUESTION [8 upvotes]: What is a good reference for flat morphisms of complex-analytic spaces? (The book by Grauert and Remmert doesn't treat them).
Topics I'm interested in: openness of flat maps, descent for coherent analytic sheaves.

REPLY [9 votes]: A reference for the fact that flat maps are open in the complex-analytic category is Theorem 2.12, p. 180 in 
C. Bănică, O. Stănăşilă: Algebraic methods in the global theory of complex spaces.
See also my answer to MO question 41158.