Kurskii Viktor Fedorovich RussiaSaratovSaratov State University , 83, Astrakhanskaya str., Saratov, 410012, Russia ilinkk@info.sgu.ru Author's articles Topological Transformation of Phase Diagrams for Сut 1 of the Quaternary System Potassium Nitrate – Water – Pyridine – Butyric Аcid in 5–60оС Equilibrium Liquid–Liquid–Solid and Critical Phenomena in the Quaternary System Cesium Nitrate+Water+Pyridine+Butyric Acid with in the Range of 5 to 60°C Extractive Crystallization of Salt and Phase Equilibria in the Ternary System Sodium Nitrate – Water – Dipropylamine