I Once Owned A Book Which I Now Regret Having Given Up

In the past decade I owned a book about important special missions in the 20th century; the second chapter was about how Erwin Rommel helped the Central Powers to win the Battle of Caporetto.
The first chapter was about an operation in the Romanian front of 1916; a German commander--let's call him Captain Potsdam--was supposed to probe for weaknesses in the Romanian lines. When he entered a village by the Danube he stumbled upon a Romanian force that proceeded to attack him. Although his force was seriously outnumbered, it put up a fierce resistance. The Germans found some Austrian prisoners in the village jail; they were given Romanian rifles and joined in the fight. Late at night a Bulgarian detachment crossed the Danube and went to the aid of Captain Potsdam; that initiative by the Bulgarian commander was most welcome, for by then the German machine guns were so overheated that they were in danger of exploding.
The fight continued into the next day, and only ended when the arrival of the German army forced the Romanians to retreat. The Austrians, Bulgarians and Germans were exhausted; amazingly, despite the ferocity of the fight, Captain Potsdam did not lose a single man. The Romanians were not so lucky, as they lost 600 dead; that fight--a mere skirmish by the standards of WWI--turned out to be a mini Verdun and a miniature Somme! More importantly, the operation did succeed in finding a weakness in the Romanian positions which the Central Powers proceeded to exploit, with the result that, by the end of 1916, Romania was overrun and the priceless oil fields of Ploesti were captured.
This was a very exciting book which unfortunately I had to sell for a mere fraction of its true value. If anybody here recognizes this description and can give me the title and author of the book I'll be extremely grateful, for I intend to order it on ebay.
God is subtle, but He is not malicious. (Albert Einstein)