R. B. Jotania, R. B. Khomane, A. S. Deshpande, C. C. Chauhan, and B. D. Kulkarni, “Physical and Magnetic Properties of Barium Calcium Hexaferrite Nano-particles Synthesized by Water-in-oil Reverse Micelle and Co-precipitation Techniques”, J. Sci. Res., vol. 1, no. 1, pp. 1–13, Dec. 2008.