Paper-based diffusive gradients in thin films technique coupled to energy dispersive X-ray fluorescence spectrometry for the determination of labile Mn, Co, Ni, Cu, Zn and Pb in river water - Almeida, Eduardo de; Nascimento Filho, Virgilio Franco do; Menegário, Amauri Antonio (Spectrochimica Acta Part B: Atomic Spectroscopy, 2012)