\[\sum_{y=-\infty}^{\infty}L^{(\alpha)}_{n}\left(cq^{y};q\right)L^{(\alpha)}_{m}%
\left(cq^{y};q\right)\frac{q^{y(\alpha+1)}}{\left(-cq^{y};q\right)_{\infty}}=%
\frac{\left(q^{\alpha+1};q\right)_{n}}{\left(q;q\right)_{n}q^{n}}h_{0}^{(2)}%
\delta_{n,m},\]