Vegetal test-system investigation on cytotoxicity of water from urban streams located in the northeastern region of Maringá, Paraná State, Brazil - doi: 10.4025/actascibiolsci.v33i1.4924. Acta Sci. Biol. Sci. 2011;33(1):71-77. doi:10.4025/actascibiolsci.v33i1.4924