docs: fix broken Markdown link

PR-URL: #10733
Closes: #10018
Reviewed-by: Athan Reines <kgryte@gmail.com>

Author: travisbreaks

lib/node_modules/@stdlib/stats/base/ndarray/variancech/README.md

@@ -199,7 +199,7 @@ console.log( v );
 
 [@chan:1983a]: https://doi.org/10.1080/00031305.1983.10483115
 
-[@schubert:2018a]: https://doi.org/10.1145/3221664.3221674
+[@schubert:2018a]: https://doi.org/10.1145/3221269.3223036
 
 </section>