Landcover changes 13C composition of riverine particulate organic matter in Piracicaba River basin (Southeast Region of Brazil) - Martinelli, Luiz Antonio; Krusche, Alex Vladimir; Ballester, Maria Victoria Ramos; Camargo, Plinio Barbosa de; Victoria, Reynaldo Luiz; Bernardes, Marcelo Corrêa; Ometto, Jean Pierre Henry Balbaud (Limnology and Oceanography, 1999)