Santos, Francisco Nóbrega dos, Ademar Pereira de Oliveira, José Ribamar Gusmão Araújo, Ovidio Paulo Rodrigues da Silva, Débora Tuane de Araújo Ferreira Silva, and Diego Almeida Medeiros. 2015. “Response of Yams Exposed to Different Sources and Doses of Nitrogen Fertilizers in the State of Maranhão, Brazil”. Semina: Ciências Agrárias 36 (6):3605-14. https://doi.org/10.5433/1679-0359.2015v36n6p3605.