Butler — A Filbert Pollinizer. Journal of the American Pomological Society, [S. l.], v. 35, n. 3, p. 109–111, 1981. DOI: 10.71318/apom.1981.35.3.109. Disponível em: https://journal.americanpomological.org/index.php/jofaps/article/view/1462. Acesso em: 22 feb. 2026.