Shorter Notices. The Pakistan Development Review, [S. l.], v. 28, n. 2, p. pp.171–174, 1989. DOI: 10.30541/v28i2pp.171-174. Disponível em: https://www.thepdr.pk/index.php/pdr/article/view/896. Acesso em: 6 dec. 2025.