Anon. 
My Secret Service, Vienna-Sophia-Constantinople-Nish-Belgrade-Asia Minor [EPUB ebook] 

In 1914, the anonymous author, a journalist by profession with no pretensions to military training, embarked on one of the most outrageous escapades of the First World War as he travelled behind German lines, collecting information on the German war machine. Across Germany, the Balkans and even so far as Turkey, meeting heads of states, ministers and even the Kaiser himself! His story may seem far-fetched, but included in his book (and reproduced with this edition) are a Vienna bread ticket of 1915, the calling card of Halil Bey, and other documents to prove his tale. However, in the modest yet dashing spirit of the times, the author was at pains to point out that "I AM not a spy, that I wish to make abundantly clear; I am a journalist, and I love my profession. Equally well I love adventure and sport, the greatest sport in the world, in which the stake is the player’s life."A jaunty read.