Columbia subject headings:
Aerodynamics, Supersonic.
Differential equations, Partial--Numerical solutions.
Differential invariants.
Gas dynamics--Mathematics.
Magnetohydrodynamics.
Nonlinear theories.
Riemannian manifolds.
Shock waves.
Wave-motion, Theory of.
Harvard subject headings:
Differential equations, Nonlinear.
Nonlinear functional analysis.
Wave equation.
Princeton subject headings:
Differential equations, Hyperbolic.
Wave equation.