Matrix norm computing complexity

Hello everyone,

I would like to get some info on how the function NORM computes the spectral norm of a matrix. More precisely, in my graduation thesis I need to estimate computational complexity of my algorithm. I guess there is the singular decomposition (svd function?) so we have 75 iterations of QR decomposition and we can deduce the computational complexity in function of the matrix size. But for the estimation in my thesis I need to refer to an official source.

Thanks in advance!