1. Growth rate and vertical propagation of the initial error in baroclinic models;Bengtsson;Tellus,1978
2. Hollett, S. R. 1975. Three-dimensional spatial correlation of P.E. forecast errors. M.Sc. thesis. McGill University, Quebec, Canada, 73 p.
3. On the dynamics of gravity oscillations in a shallow water model, with application to normal mode initialization;Machenhauer;Contr. Atmos. Phys.,1977
4. Temperton, C. and Williamson, D. 1979. Normal mode initialization for a multi-level grid point model. European Centre for Medium Range Weather Forecasts Technical Report No. 11, 91 p. Available from ECMWF.