March 2015
Just bumping up this thread as I have exactly the same problem as you. Thanks for your input.
I'm level18 and have been doing only one quest for the last 8 hours: finding this last god'm venatori tome and it's literally impossible. I've checked at all the book shop, I've killed hundreds of venatoris, not a single drop of the last tome.
This is clearly a poor programming from Bioware and it's incredibly frustrating. Even more frustrating because this game is insanely good, every minute of play is a joy and knowing I will never be able to get the rift mage specialisation drives me crazy.
This thread has been going on for more than 3 months, and you can find many similar topics on other forum but the developers decided to not fix this bug (I've installed the last update and it didn't change anything) and let us in our misery. Such a lack of respect for their true fans and players, quite disappointing.
June 2019
June 2022
Randomly found the last one in "Hissing Wastes". Don't give up, friends!
July 2022