Piekarski, Paweł, and Zbigniew Zwoliński. “Temporal Variation in Vegetation Indexes for Pine and Beech Stands During the Vegetation Season, Szczecin Lowland, Poland”. Quaestiones Geographicae, vol. 33, no. 3, Sept. 2014, pp. 131-43, doi:10.2478/quageo-2014-0037.