Added a bit of interpolation spaces.

src/dg/complex/zero.tex

@@ -105,7 +105,7 @@
 
     then for each $s \in [0, 1]$, $M(s) \le M(0)^s M(1)^{1-s}$. 
 \end{lemma}
-\begin{proof}
+\begin{proof}[Proof, {{\cite[Theorem VI.3.7]{ConwayComplex}}}. ]
     Assume without loss of generality that $M(0), M(1) > 0$. Let
     \[
     g: \complex \to \complex \quad z \mapsto M(0)^z M(1)^{1 - z}