1 files changed, 2 insertions, 1 deletions

diff --git a/mgr.tex b/mgr.tex
index 8b626dc..3556e3c 100644
--- a/mgr.tex
+++ b/mgr.tex
@@ -304,7 +304,8 @@ We make use of a fundamental theorem tying MSO logic on trees and tree automata:
 
 We note that the converse of this theorem is also true (i.e. that for every tree
 automaton, there is a corresponding MSO formula), however we will use only the
-MSO to automata direction in this work.
+MSO to automata direction in this work. See for example Bojańczyk's text
+\cite{bojanczyktoolbox} for a proof of both directions.
 
 \section{Query answering problems}\label{query-answering-problems}