Equivalence of ordered and unordered cech cohomology.

I wrote it up for my algebraic geometry course as a 2-page handout, inspired by EGA $0_{\rm{III}}$, 11.8.7 (which isn't to say this is a canonical reference; just some written reference...).

I'd say that a canonical reference is Roger Godement's Topologie algébrique et théorie des faisceaux, §3.8, chapter I.

A recent reference is Corollary 5.2.4 in Liu's "Algebraic geometry and arithmetic curves."

However, for the proof of the main step (reducing from cochains to alternating cochains, as in Brian Conrad's writeup) it refers to Serre's "Faisceaux Algébriques Cohérents‎", no. 20, Proposition 2.