Let $\text{SO}\_{p,q}$ be the special orthogonal group of type $(p,q)$. In [D. Prasad's lecture notes on algebraic groups](http://www.math.tifr.res.in/%7Edprasad/alg-grp.pdf) the statement
$$\text{"The group $\text{SO}(p, q)$ is quasi-split if and only if $|p − q| ≤ 2$."}$$
is given without proof or further explanation. 


Does anyone have a reference to the proof of this result? Any help would be greatly appreciated.


N.B.: I have already (unsuccesfully) asked a similar [question](https://math.stackexchange.com/questions/1900821/conditions-under-which-the-special-orthogonal-group-textso-p-q-is-quasi-s) on math.stackexchange



Condition for quasi-splitting of special orthogonal group
Since the OP asked for a reference, I would like to provide some. First of all, a group is quasi-split iff its Satake diagram does not contain black dots. The list of Statake diagrams can be found in many places but most of them are difficult to understand out of context. Of the more useful kind are the tables in


Onishchik, A. L.; Vinberg, Ėrnest Borisovich (1994), Lie groups and Lie algebras III: structure of Lie groups and Lie algebras


For the theory, I found Section 29 of Daniel Bumps book on Lie groups quite useful (see in particular p. 294ff)


