Here are a few of the latest books on the 1914 July Crisis:
Christopher Clark, The Sleepwalkers: How Europe Went To War In 1914.
Max Hastings, Catastrophe: Europe Goes to War.
Margaret MacMillan, The War That Ended Peace: The Road to 1914.
July 1914: Countdown to War.
Thomas Otte, July Crisis: The World’s Descent into War, Summer 1914.
You can also have a look at my ebook on German decision-making during the July Crisis:
Matthieu Santerre, World War I: How Germany Blundered into War (Second Edition)
Available on Amazon.