If the product your selling REQUIRES an additional product, common sense would tell you to; clearly list where to find it or provide a link to that product. I would think that if you were trying to sell something based on someone else's item, you'd want to give them an equal opportunity to make a profit as well. Especially since, if it wasn't for them you wouldn't have said product to create from. Now, if you've violated their copyright terms - that might be a reason not to provide the information. (Just a thought, not pointing fingers at anyone)

Just enjoying the Vue. :0)