\[
\boxed{
{x}^{3}{\frac {{\rm d}^{3}}{{\rm d}{x}^{3}}}y \left( x \right) + \left( -{\nu}^{2}+1 \right) x{\frac {\rm d}{{\rm d}x}}y \left( x \right) + \left( a{x}^{3}+{\nu}^{2}-1 \right) y \left( x \right) =0}
\]