diff --git a/src/measure/radon/c0.tex b/src/measure/radon/c0.tex
index bd39ad0..470d687 100644
--- a/src/measure/radon/c0.tex
+++ b/src/measure/radon/c0.tex
@@ -47,7 +47,7 @@
 
     is an isometric isomorphism. 
 \end{theorem}
-\begin{proof}
+\begin{proof}[Proof {{\cite[Theorem 7.17]{Folland}}}. ]
     Let $f \in C_0(X; \complex)$, then
     \[
     \abs{\int f d\mu} \le \int \norm{f}_u d\mu \le \norm{f}_u \cdot |\mu|(X)