FENG, Zexu. Research on the S&P 500 Index Based on LSTM and GRU. Highlights in Business, Economics and Management, [S. l.], v. 21, p. 38–48, 2023. DOI: 10.54097/hbem.v21i.13601. Disponível em: https://drpress.org/ojs/index.php/HBEM/article/view/13601. Acesso em: 27 jul. 2026.