\[\int_{a}^{b}e^{-xp(t)}q(t)\,\mathrm{d}t\sim e^{-xp(a)}\sum_{s=0}^{\infty}%
\Gamma\left(\frac{s+\lambda}{\mu}\right)\frac{b_{s}}{x^{(s+\lambda)/\mu}},\]