I've tried this with Pokemon and another game, and Krisp is absolutely right.
You cannot use a GBA or GBASP to link two GBC games. Like I said, I tried this with Pokemon and two Yugioh games with the same name and it didn't work. I think the reasoning behind this is that since the ports are different sizes, the game does not recognize the port and thus the link cannot be established.
However a GBA or GBASP can work for all other normal gameplay purposes of a GBC game.
I believe this is a suitable answer. There will probably be no questions left to ask...