Are these relations of associated Legendre polynomials correct?

Question

Is the relation
$$\lim_{x\rightarrow 1}\frac{Q_n^m(x)}{P_n^m(x)}=\frac{\pi}{2}\cot m\pi$$
correct? Here $P$ and $Q$ are the associated Legendre polynomials of the first ans second kind respctively. Do anybody know how to prove it or the references that I can refer?
 

Comments

where do you get the formula from? http://dlmf.nist.gov/14.9 might help to answer your question