Ol’khovik, L. P.; Borisova, N. M.; Golubenko, Z. V.; Mozul, K. A.; Sizova, Z. I.; Shurinova, E. V. Magnetic Anisotropy of an Ensemble of Ca-Substituted Barium Hexaferrite Nanoparticles. Physics 2017, 1135, 44-48.