Freitag, M. and B. Hofmann. "Analytical and numerical studies on the influence of multiplication operators for the ill-posedness of inverse problems" Journal of Inverse and Ill-posed Problems jiip, 13.2 (n.d.): 123-148. Retrieved 24 May. 2013, from doi:10.1515/1569394053978524

Freitag, M. & Hofmann, B. (n.d.). Analytical and numerical studies on the influence of multiplication operators for the ill-posedness of inverse problems. Journal of Inverse and Ill-posed Problems jiip, 13(2), pp. 103-200. Retrieved 24 May. 2013, from doi:10.1515/1569394053978524

Freitag, M. and B. Hofmann. n.d.. Analytical and numerical studies on the influence of multiplication operators for the ill-posedness of inverse problems. Journal of Inverse and Ill-posed Problems jiip. 13(2): 103-200. Retrieved 24 May. 2013, from doi:10.1515/1569394053978524