K. Krupa, W. Szwerc, P. Nizinski, K. Slowik, A. Błazewicz, and R. Kocjan, “Assessment of Concentration Changes of Selected Elements in Birch Sap, Depending on Collection Day, Using Atomic Absorption Spectrometry”, Curr. Issues Pharm. Med. Sci., vol. 31, no. 2, pp. 57–60, Jun. 2025, doi: 10.1515/cipms-2018-0012.