Influence of the wurtzitic boron nitride initial structural state on the formation of the granular structure of the wBN based materials. I. Structural characteristics of particles of the initial wBN powders - G. S. Olejnik; V. M. Volkogon; Ju. A. Fedoran; S. K. Avramchuk; A. V. Kravchuk; A. V. Kotko (Superhard Materials, 2013)