Lu Yang Samir Attallah George Mathew Karim Abed-Meraim Analysis of Orthogonality Error Propagation for FRANS and HFRANS Algorithms. 4515-4521 2008 56 IEEE Transactions on Signal Processing 9 http://dx.doi.org/10.1109/TSP.2008.923199 db/journals/tsp/tsp56.html#YangAMA08