$4a^{2}b^{2}-(a^{2}+b^{2}-c^{2})^{2}$
There is a difference o squares but after factoring it, I can't find a way to get to the answer: $(c-a+b)(c+a-b)(a+b-c)$
What I Did: $(2ab)^{2}-(a^{2}+b^{2}-c^{2})^{2}$
$(2ab+a^{2}+b^{2}-c^{2})( 2ab-a^{2}-b^{2}+c^{2})$
After this step I couldn't find any idea. Could you give me a hint please?
Edit: I found something: $2ab+a^{2}+b^{2} = (a+b)^{2}$
HINT
$$(2ab+a^{2}+b^{2}-c^{2})( 2ab-a^{2}-b^{2}+c^{2})=[(a+b)^2-c^{2}][c^2-(a-b)^2]$$