Quadratic Problem with consraints

Hey,

I'm trying to implement an article and I have some issues. I need to find solution to the following quadratic minimization problem:

argmin_(n) = sum(over all z's){ <n,J(z)>^2 + delta<n,A>^2}
such that ||n||^2.

Where,

n's dimension is 1x3 - (unknown),
J(x)'s dimension is 3x1- (known),
A's  dimension is 3x1 - (known),
delta is scalar - (known).

Any help will be great.

Thank's