Insert internal reference

Thanks to Wataru
https://stacks.math.columbia.edu/tag/05EG#comment-8827

more-algebra.tex

@@ -23606,6 +23606,7 @@ \section{Formal glueing of module categories}
 we can find a surjection $M' \to M$ with $M'$ a direct sum of
 modules of the form $R/I^n$. Using the long exact sequence of
 Homology, Lemma \ref{homology-lemma-six-term-sequence-ext}
+and using Lemma \ref{lemma-neighbourhood-equivalence}
 we see that it suffices to prove the lemma for $M'$.
 Using compatibility of $\Ext$ with direct sums (details omitted)
 we reduce to the case where $M = R/I^n$ for some $n$.