KOPPINEN, M.; NEUVONEN, T. An imprimitivity theorem for Hopf algebras. Mathematica Scandinavica, Berkeley, CA, United States, v. 41, p. 193–198, 1977. DOI: 10.7146/math.scand.a-11713. Disponível em: https://journals.msp.org/mscand/article/view/1934. Acesso em: 25 jul. 2026.