1. Geographical interpretation of measurements of average phase velocities of surface waves over great circular and great semi circular paths;Backus;Bull. seism. Soc. Am.,1964
2. Baig , A. Dahlen , F.A. Hung , S.H. 2000 The efficacy of Born kernels for computation of traveltimes in random media abstract at AGU 2000 Fall meeting S62A-01
3. The spectra of unresolved split normal mode multiplets;Dahlen;Geophys. J. R. astr. Soc.,1979