\bibitem{Dysthe02}     D.K.~Dysthe, Yu.~Podladchikov, F.~Renard, J.~Feder, B.~Jamtveit, \hskip 2mm
                       {\it Universal Scaling in Transient Creep},
                       Phys. Rev. Lett. {\bf 89} (24), 246102, 2002.