 Complete the following phrase:  The 23rd Anti-Tank Regiment was an Australian Army anti-tank artillery regiment that was raised for service during the Second World War as part of the all volunteer Second Australian Imperial Force. It was formed in July 1940, and was assigned to the 8th Division, but was later reassigned to the 9th Division. With this formation, the regiment took part in the Siege of Tobruk in 1941 and then the First and 