KOPPINEN, M. A Note on Inner Coalgebra Measuring and Derivations. Mathematica Scandinavica, Berkeley, CA, United States, v. 76, p. 201–204, 1995. DOI: 10.7146/math.scand.a-12535. Disponível em: https://journals.msp.org/mscand/article/view/1089. Acesso em: 25 jul. 2026.