Levonyan, L.V., and H.M. Manukyan. 2017. “FEATURES OF DIFFRACTION FOCUSING OF A SPHERICAL X-RAY WAVE ON A SHORT PERIOD SUPERLATTICE”. Proceedings of the YSU A: Physical and Mathematical Sciences 51 (1 (242). Yerevan, Armenia:113-16. https://doi.org/10.46991/PYSU:A/2017.51.1.113.