Gnomish Engineering problem.

Hello guys. So today I reached 200 skill in engineering and figured I'd take gnomish. Took the quest from the trainer in SW that I think gave me a book, manual of engineering disciplines and told me to go IF. I'm not sure if I had to read the book, and I didn't, so I returned the quest in IF and didn't receive Gnomish. Now I don't know what to do, tried going to the NPC in Tanaris at which you can "re-spec" but I can't use the book on the table. Also tried going to the npc in SW, which doesn't give me the quest again.. Anyone got an idea what I should do? I'm pretty sure I had to read the book. And if I had to, any method to get it again? Much appreciated.