Recommended reading for fans of The History of the Twentieth Century. These are some of my favorite sources for the Great War portion of the podcast (1901-1914):

A World Undone: The Story of the Great War, 1914-1918
by G.J. Meyer

The Great War
by Peter Hart

The First World War
by Hew Strachan

The First World War
by John Keegan

Four of the most recent and most authoritative studies of the Great War. I used all of these extensively.

The Guns of August
by Barbara Tuchman
One of the greatest history books ever written, by the patron saint of The History of the Twentieth Century. When it was determined that it was ineligible for a Pulitzer Prize in history, the Pulitzer committee awarded it the Pulitzer Prize for literature, instead. The drama of the first month of the war, when it seemed anything could happen.

The Zimmermann Telegram
by Barbara Tuchman
Detailed account of the sequence of events that brought the USA into the Great War. It had far less to do with the sinking of Lusitania than with clumsy German and deft British espionage.

World War I: The African Front: An Imperial War on the Dark Continent
by Edward Paice
Definitive account of the most neglected theater of the Great War

The Peace to End All Peace: The Fall of the Ottoman Empire and the Creation of the Modern Middle East
by David Fromkin

The Ottoman Endgame: War, Revolution, and the Making of the Modern Middle East
by Sean McMeekin

Two valuable accounts of how the Allies reorganized the Middle East and created the nations (and the conflicts) we know today.

Woodrow Wilson
by John Milton Cooper, Jr.
The most authoritative Wilson biography by the leading Wilson scholar.

Dreams of a Great Small Nation: The Mutinous Army that Threatened a Revolution, Destroyed an Empire, Founded a Republic, and Remade the Map of Europe
by Kevin J. McNamara
David Lloyd George called it “one of the greatest epics of history,” the story of how the Czech and Slovak independence movements went from a handful of persecuted dissidents within a huge empire to a free and independent nation that took its place alongside the Allies in the war against the Central Powers.