It is well known that SAGBI/Gröbner bases are important for commutative and non-commutative algebra. The references for commutative scenery is ample and vast, but I am in trouble to find a good reference for the general theory of SAGBI/Gröbner bases for non-commutative setting. Actually, I am interesting in the following subjects:

(1) Where can I find the general construction of these bases for non-commutative setting?

(2) Is there some reference for the specific case of the Universal enveloping algebra of a finite-dimensional semi-simple Lie algebra over $\mathbb{C}$?

(3) Does exist a reference using this bases in representation theory? For instance, in the study of universal objects defined by generators and relations.

THANKS!