TY JOUR TI Far fields of internal gravity waves from a source moving in the ocean with an arbitrary buoyancy frequency distribution KW Internal gravity waves KW stratified ocean KW far fields KW asymptotics JO Russian Journal of Earth Sciences AU Bulatov, V.V. AU Vladimirov, Y.V. AU Vladimirov, I.Y. PY 2019 IS 19 PB Geophysical Center of the Russian Academy of Sciences