\[W_{n,2}(u,\xi)=\operatorname{Bi}\left(u^{2/3}\xi\right)\left(\sum_{s=0}^{n-1}%
\frac{A_{s}(\xi)}{u^{2s}}+O\left(\frac{1}{u^{2n-1}}\right)\right)+%
\operatorname{Bi}'\left(u^{2/3}\xi\right)\left(\sum_{s=0}^{n-2}\frac{B_{s}(\xi%
)}{u^{2s+(4/3)}}+O\left(\frac{1}{u^{2n-1}}\right)\right).\]