Application of handheld XRF spectrometers for estimation of Rare Earth Elements content in alkaline intrusions from the East European Craton (NE Poland) – preliminary results - Pańczyk, Magdalena; Bazarnik, Jakub; Giro, Leszek; Nawrocki, Jerzy; Krzemińska, Ewa (Geology, Geophysics and Environment, 2015)