Citation Hunt

The Wikipedia snippet below is not backed by a reliable source. Can you find one?

Click I got this! to go to Wikipedia and fix the snippet, or Next! to see another one. Good luck!

In page Battle of Ortona:

"

Mouse-holing also allowed the soldiers to progress through the town, building by building, without entering the streets where they would face enemy fire.[5] While some sources attribute the strategy to the Canadian forces, a British training film of 1941 had already illustrated the concept. The Canadians were certainly early, effective and courageous users of the technique.[6] Throughout the battle, engineers on both sides also used the brutal but effective tactic of using demolition charges to collapse entire buildings on top of enemy troops.[7][8]