A copy of this work was available on the public web and has been preserved in the Wayback Machine. The capture dates from 2005; you can also visit the original URL.
The file type is application/pdf.
T. Tokle, C.R. Davidson, M. Nissov, J.-X. Cai, D.G. Foursa, A. Pilipetskii. "Transmission of RZ-DQPSK over 6500 km with 0.66 bit/s/Hz spectral efficiency." IEEE/LEOS Workshop on Advanced Modulation Formats, 2004