JOCKUSCH, C. G. ,. J. A Reducibility Arising from the Boone Groups. MATHEMATICA SCANDINAVICA, [S. l.], v. 31, p. 262–266, 1972. DOI: 10.7146/math.scand.a-11433. Disponível em: https://www.mscand.dk/article/view/11433. Acesso em: 4 may. 2024.