See The Australian War Memorial’s First World War Nominal Roll Data Base http://www.awm.gov.au/database/133.asphttp://www.awm.gov.au/database/133.asp Enter Cooper into the search engine. Click on the search button. Click on Page Number 11-022. Scroll down to 6035 Pte Cooper, Louis Vernon 12th Batallion Enlisted 19/2/16 Returned to Australia 16/6/19
You can print this page out with the printer-friendly button at the top.
If you decide you would like a copy of Louis’ service records, also click National Archives of Australia hyperlink at the top. This explains what is contained in the service records and has a World War I Service Request Form hyperlink about two-thirds of the way down the page.