SCHMIDT, Asmus L. On the Approximation of Quaternions. Mathematica Scandinavica, Berkeley, CA, United States, v. 34, p. 184–186, 1974. DOI: 10.7146/math.scand.a-11519. Disponível em: https://journals.msp.org/mscand/article/view/2124. Acesso em: 25 jul. 2026.