Quote Originally Posted by Geoffrey S
If it's any help, I've just reserved some books which I'll look through for anything useful. It does certainly seem most books are in French or German - though that makes it more difficult to find literature rather than reading it once found. I know of at least two local uni professors who are experts on Yemen, at least one of whom has recently given lectures on ancient waterworks. Time permitting I could ask around.
I've even had emails back and forth with Breton himself - and I tried a number of grad students he suggested, as well as some other professors who specialize in the area. But none were interested in helping out in any way really.