BUTLER, David; BUTLER, Robert. The Relative Age Effect and Under-21 Irish Association Football: A Natural Experiment and Policy Recommendations. The Economic and Social Review, [S. l.], v. 46, n. 4, Winter, p. 511–519, 2015. Disponível em: https://esr.ie/index.php/esr/article/view/453. Acesso em: 19 feb. 2026.