# References on wave solutions in continuum mechanics [closed]

I am interested in literature on known wave solutions in continnum mechanics, precisely the following mechanical equation: $$\rho\partial_t^2u_i = C_{ijkl}\nabla_j\nabla_ku_{l}$$ My interest is spread around its study for cubic lattices, which doesn't seem straightforward to solve analytically to me. But I couldn't find a reference book or articles illustrating a peculiar solution of it.

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