GALE, David. The law of supply and demand. Mathematica Scandinavica, Berkeley, CA, United States, v. 3, p. 155–169, 1955. DOI: 10.7146/math.scand.a-10436. Disponível em: https://journals.msp.org/mscand/article/view/2884. Acesso em: 8 sep. 2026.