I'm writing something and I need to refer to a mathematical fact; unfortunately I got it from Wikipedia, which does not source the specific piece of info! It relates to a choice of simple roots for $\mathfrak{su}(N)$ being the $N-1$ vectors given by $(1,-1,0,0,...,0)^T$, $(0,1,-1,0,...,0)^T$, ..., $(0,0,...,1,-1)^T$ (all of dimension $N$).
My question is: is there a standard text people refer to in these circumstances? Can anyone give me a go-to book? Thanks in advance.
One of many references is the book Lie Groups Beyond an Introduction, by Anthony W. Knapp. Appendix $C$ gives data for simple Lie algebras (page 508 ff).