JOHNSON, E. W.; JOHNSON, J. A.; TAYLOR, M. B. $P$-systems in lattice modules. Tamkang Journal of Mathematics, [S. l.], v. 34, n. 3, p. 197–200, 2003. DOI: 10.5556/j.tkjm.34.2003.310. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/310. Acesso em: 3 dec. 2024.