\[\operatorname{Bi}\left(z\right)=\frac{1}{2\pi}\int_{-\infty}^{\infty e^{\pi i/%
3}}\exp\left(\tfrac{1}{3}t^{3}-zt\right)\,\mathrm{d}t+\dfrac{1}{2\pi}\int_{-%
\infty}^{\infty e^{-\pi i/3}}\exp\left(\tfrac{1}{3}t^{3}-zt\right)\,\mathrm{d}t.\]