Craven and Cate produced a seven-volume history that constitutes the official record of the Army Air Forces participation in World War II. Among historical records, this is an invaluable resource. Finding and buying print copies can be very difficult and extremely expensive. Craven and Cate comprises seven volumes and many thousands of pages.
Fortunately for historians and history buffs, the USAF has digitized the entire work and made it available to the public free of charge in .pdf format.
It is a huge work and it is a huge download, roughly a full gigabyte of material. If you have high-speed cable access (my optimum online service supports 1.3 meg/sec download speed) expect to need about 15 to 20 minutes to download all seven volumes if you have the typical cable service. Those of you with DSL should plan on two or three hours. If you have dial-up... get a friend with cable to download the individual volumes and save them to a pair of CDs or a DVD unless you have a week to kill and a cell phone....
I am fortunate to have a complete set in book form (cost me a fortune 10 years ago), but the .pdf format allows for cut and pasting as well as quick searches.
You can download the seven volumes
HERE. Here is a sample page from volume 3.

My regards,
Widewing