DAHL, A. Review of Environment: Patrimoine de l’humanité by Association d’etudes Bahá’íes—Europe. The Journal of Bahá’í Studies, Ottawa, Ontario, Canada, v. 5, n. 4, 1993. DOI: 10.31581/jbs-5.4.8(1993). Disponível em: https://journal.bahaistudies.ca/online/article/view/188. Acesso em: 3 aug. 2021.