Goblin Engineering Quest Bug

Hello. A while ago I took the quest for the Goblin Engineering, but for some I don`t know what reason I canceled it and now I cannot find it anymore, anywhere; only the Gnomish Engineering quest is available. Any help/suggestions?

LE: Contacted a GM and he told me to do the quest "Show me your work" from which I gained Gnomish Engineering;this quest is useless for me because I need Goblin in order to be able to purchase the plans for Shatter Rounds, as I have a gun and I am a hunter. Is there any way I can switch from Gnomish to Goblin Engineering without unlearning the whole profession?

Thank you!

Please someone answer!