People often forget that, during World War 2, the Axis powers were NOT just Germany, Italy and Japan. There was Finland, Hungary, Rumania, Thailand.........and then there was Bulgaria. This superb book along with the equally solid  THE BULGARIAN AIR FORCE IN WORLD WAR: GERMANY'S FORGOTTEN ALLY by Martinez tell the story of Bulgaria's air force which met American planes in the skies of Europe before finally surrendering in 1944. Excellent illustrations. Much heretofore unknown history that is a must for any serious WW 2 buff. The 2 best books on Bulgaria in WW 2.