STUDY THE PROPERTIES OF THERMOTROPIC LIQUID CRYSTALS INDUCED BY HYDROGEN BONDING BETWEEN PYRIDYL- HETEROCYCLIC DERIVATIVES AND BENZOIC ACID, 4-HEPTYLOXYBENZOIC ACID OR 4-OCTYLOXYBENZOIC ACID. (2018). Al-Nahrain Journal of Science, 13(4), 62-69. https://anjs.edu.iq/index.php/anjs/article/view/971