Reddit mentions of Winged Defense: The Development and Possibilities of Modern Air Power--Economic and Military (Alabama Fire Ant)

In defense of strategic bombing:

Command of the Air by Giulio Douhet. Douhet was the tip o the spear in advocating an independent mission for air forces who claims that wars can be won before ground troops are even needed.

Winged Defense by Billy Mitchell. Mitchell was the prophet of strategic bombing and advocate of an independent air force in the United States (to the chagrin of the Army at the time).

In defense of airpower as "close air support" for ground troops:

Winning With Allies: The Strategic Value of the Afghan Model. Air power can be highly effective in a close air support role and can tip the balance on the ground, even in support of a weak-ish client.

Breaker of Armies: Air Power in the Easter Offensive and the Myth of Linebacker I and II in the Vietnam War. Essentially the same argument as above.

A counter argument for the two above is: Allies, Airpower, and Modern Warfare: The Afghan Model in Afghanistan and Iraq

Academic analysis of air power theory, its evolution and effectiveness:

Bombing to Win By Robert Pape. Been a while since I've read this one. From what I remember he is critical of the theories that say air power can win wars all by themselves by bombing cities and economic nodes, but is most effective in an interdiction role.

Fast Tanks and Heavy Bombers
Innovation in the U.S. Army, 1917–1945 by David E. Johnson. He traces the efforts of those who wanted an independent air force in the U.S. during the interwar period (tho not the sole focus of the book). I loved this book, very good at showing the bureaucratic hurdles in the way of advocates of strategic bombing and an independent air force.



Disclaimer: This is not all there is to know on air power, just the things I have read myself.