Algebraic Topology
《Algebraic Topology》 · 第 257 页 · Section 3.3
For open covers \(\mathcal U\) of \(X\), the direct limit \(\varinjlim_{\mathcal U}H^i(N(\mathcal U);G)\) over refinements is by definition the Čech cohomology group \(\check H^i(X;G)\).