Changes in the mineral and trace element contents of cereals, fruits and vegetables in Finland
Ekholm, Päivi; Reinivuo, Heli; Mattila, Pirjo; Pakkala, Heikki; Koponen, Jani; Happonen, Anu; Hellström, Jarkko; Ovaskainen, Marja-Leena (Academic Press, 2007)