Hi Aviator!
The book I meant is the good, old "ACE-The Technical Pilot Interview" (sorry for the confusing abbreviation !!).
They called about 5 weeks before the interview and I applied for both, DESO and DEFO.
I was surprised, too, that it was so quick!
Friend of mine had an invitation for AMS in march, so they hold interviews in europe quiet often. Should not be to long until it is your turn!!
Good luck!
FranzJuppchen