Oliveira, H. do V. de (2008) “Alterations in calcium, magnesium and potassium contents in a red-yellow clay soil irrigated with a fish-culture effluent in a protected environment”, Revista em Agronegócio e Meio Ambiente, 1(2), pp. 231–240. doi: 10.17765/2176-9168.2008v1n2p231-240.