Medeiros Pina Ximenes, Patrícia de Souza, Antonio Samuel Alves da Silva, Tatijana Stosic, Jackson Freitas de Amorim, and Rômulo Simões Cezar Menezes. 2019. “Analysis of Drought Severity in Agreste Pernambucano Using Standardized Precipitation Index”. Sigmae 8 (2):331-39. https://publicacoes.unifal-mg.edu.br/revistas/index.php/sigmae/article/view/950.