Sources:

World War I: A Student Encyclopedia
By Spencer Tucker

British Artillery on the Western Front in the First World War: 'The Infantry cannot do with a gun less'
by Sanders Marble

Vimy Ridge: A Canadian Reassessment
edited by Geoffrey Hayes, Andrew Iarocci, Mike Bechthold

https://www.veterans.gc.ca/eng/remembrance/history/first-world-war/fact_sheets/vimy

http://www.hill70.ca/Battle-of-Hill-70/Hill-70-Gallery/Battle-Maps/Creeping-Barrage.aspx

https://ww1.habsburger.net/en/chapters/artillery-ii-creeping-barrage-barrage-and-curtain-fire