A Classification of Hardy North American Apple Cultivars Based on Hardiness Zones. Journal of the American Pomological Society, [S. l.], v. 29, n. 4, p. 78–108, 1975. DOI: 10.71318/apom.1975.29.4.78. Disponível em: https://journal.americanpomological.org/index.php/jofaps/article/view/1228. Acesso em: 11 dec. 2025.