Chlorophyll a fluorescence and ultrastructural changes in chloroplast of water hyacinth as indicators of environmental stress - Lage-Pinto, Frederico; Oliveira, Jurandi G; Da Cunha, Maura; Souza, Cristina M. M; Rezende, Carlos E; Azevedo, Ricardo Antunes; Vitória, Angela P (Environmental and Experimental Botany, 2008)