1. 11B/10B MEASUREMENTS BY NEGATIVE ION MASS–SPECTROMETRY. Authors: MACIEJ CZARNACKI, STANISLAV HALAS.2. ABOUT ISOTOPE EQUILIBRIUM BETWEEN VAPOR AND LIQUID PHASES. Authors: STANISLAV HALAS.3. TENTATIVE INVESTIGATIONS OF CHLORINE ISOTOPE RATIO. Authors: ANDRZEJ PELC, STANISLAV HALAS.