G. Török, G. Parlagh, and L. G. Nagy, “DETERMINATION OF WEAK BETA EMITTERS BY LIQUID SCINTILLATION COUNTING TECHNICS Ill. INVESTIGATION OF ORGANIC CRYSTAL AND PLASTIC FLOW CHAMBER DETECTORS”, Period. Polytech. Chem. Eng., vol. 13, no. 3, pp. 249–260, Jan. 1969.