"The source problem"---transient waves propagating frominternal sources in non-stationary media.
Direct scattering of propagating transient waves originating from internal sources in non-stationary, inhomogeneous, dispersive, stratified media is investigated. The starting point is a general, inhomogeneous, linear, first order 2 X 2 system of equations. Particular solutions are obtained, as integrals of fundamental waves from point sources distributed throughout the medium. First, resolvent ke