Reference. Clifford algebra analogue of the Hopf--Koszul--Samelson theorem [kostant1997clifford]

@article{kostant1997clifford,
 title = {Clifford Algebra Analogue of the Hopf--Koszul--Samelson Theorem},
 author = {Kostant, Bertram},
 year = {1997},
 journal = {Advances in Mathematics},
 volume = {125},
 number = {2},
 pages = {275--350},
 doi = {10.1006/aima.1997.1602}
}