DZINOTYIWEYI, Heneri A. M. Weakly almost periodic functions and irregularity of multiplication in semigroup algebras. Mathematica Scandinavica, Berkeley, CA, United States, v. 46, p. 157–172, 1980. DOI: 10.7146/math.scand.a-11859. Disponível em: https://journals.msp.org/mscand/article/view/1783. Acesso em: 25 jul. 2026.