. "Acoustical axes in weakly anisotropic media in the first-order approximation." . . "637391" . . . "Acoustical axes in weakly anisotropic media in the first-order approximation."@en . . . "Acoustical axes in weakly anisotropic media in the first-order approximation." . "perturbation theory; acoustical axes; weak anisotropy"@en . "Univerzita Karlova v Praze" . . "Seismic waves in complex 3-D structures. Report 12." . . "0"^^ . "P(GA205/00/1350), Z(AV0Z3012916)" . "0"^^ . "2"^^ . "Prague" . "RIV/67985530:_____/02:03020046!RIV/2003/AV0/A03003/N" . "1"^^ . "Acoustical axes in weakly anisotropic media in the first-order approximation."@en . . "RIV/67985530:_____/02:03020046" . "(1)" . . . "151;170" . "Perturbation theory is a useful tool for approximate study of wave properties in weakly anisotropic media. Especially its first-order approximation yields simple and transparent formulae only slightly more complicated than those for isotropic media."@en . "Perturbation theory is a useful tool for approximate study of wave properties in weakly anisotropic media. Especially its first-order approximation yields simple and transparent formulae only slightly more complicated than those for isotropic media." . "P\u0161en\u010D\u00EDk, Ivan" . . . . . . "Farra, V." . "[F408FE81E7C3]" . "20"^^ . .