Context:

The episode opens with a quote from Edward Spears' reminiscences about a crucial exchange on September 5th, 1914. Spears was a British liaison officer with the French army, and the quote describes General Joffre's plan. This appears to be from his published memoirs about his WWI experiences.

Context:

Referenced multiple times throughout the episode as a source for WWI history. Explicitly mentioned as 'Max Hastings' book' when discussing details about the Battle of the Marne, including quotes about Lieutenant Lionel Tennyson, abandoned German vehicles, and the gunner Paul Lantier. Max Hastings is a well-known military historian.

Context:

Explicitly mentioned as a book written in 1956 by Jean Dutour, who claimed the taxis of the Marne was 'the single greatest event of the 20th century.' The book is discussed in the context of how this WWI legend became important to French national identity.