Locating Ignition Coils

I had a diagnosis done to my 99 maxima and was told that I had to have my ignition coils replaced. They told me how much it was going to cost, so I went and bought a manual to find out how to replace them myself. The manual shows how to replace them, but doesn't show where they are exactly. I know that three of them are in plain view at the top side of the engine, but I can't find the other three.
If anyone has any idea where they are located, please reply.

the front 3 are under the Plastic cover on the Valve cover, and the back 3 are on the back side of the Intake manifold.