Air War Over Spain [first edition]

"The author of this book has given particular emphasis to the part played by aviation in the Spanish Civil War if 1936-39, but in so doing has opened a door through which we may catch a glimpse of some of the grim realities facing the opposing factions. This alone is sufficient to make the book highly readable. More significant, however, is the fact that it was during this period in Spain's history that the Luftwaffe experimented with the Blitzkrieg techniques which, in the early days of the second World War, were to make the German war machine seem invincible."