Forgive me if I've mentioned this before and/or it has been discussed in these hallow halls in the past, but I cannot stress anymore that this book,
Hostile Skies - A Combat History of the American Air Service in World War I by James J. Hudson, is a great treatment on this topic.
For the purists, this not only details the exploits of the Pursuit Groups, but also those exploits of the Observation and Balloon Groups, too; the oft overlooked and unsung 'other' heroes of the war.
Written in 1968, it is still in print today (at least that's what BN & Amazon show...)(mine is a borrowed copy from the houston Public Library) and Mr. Hudson , a member of Cross & Cockade, references the C&C a lot, amongst other sources.
The short of it is, if one is looking for a good source of information that is well researched and documented, then this is a worthy book to peruse.
As to the veracity of said information and content, I leave that for the more well versed in these matters to enlighten. As a matter of record, I'd really welcome the opinion of the more well versed here as to whether I should keep extolling its virtues.
I understand there are those who sell snake oil out there and I'd hate to think this tome is among those products.