P. Bassia, I. Pitas, and N. Nikolaidis, ”Robust audio watermarking in the time domain,” IEEE Trans. Multimed., vol.3, no.2, pp.232-241, 2001.
S. Shin, O. Kim, J. Kimand, and J. Choil, ”A robust audio watermarking algorithm using pitch scaling,” Proc. IEEE 14th Int. Conf. Digital Signal Processing, pp.701-704, 2002.