1. I. Johnson and H.M. Feder: Trans. TMS-AIME, 1962, vol. 224, pp. 468–73.
2. I. Johnson: Proc. 2nd Conf. on Rare Earth Research, J.F. Nachman and C.E. Lundin, eds., Gordon and Breach, New York, NY, 1962, p. 130.
3. L.J. Wittenburg and G.R. Grove: USAEC, MLM-1964, vol. 1208, pp. 8–11.
4. I. Johnson, M.G. Chasanov, and R.M. Yonco: Trans. TMS-AIME, 1965, vol. 233, pp. 1408–14.
5. I. Johnson, K.E. Anderson, and R.A. Blomquist: Trans. ASM, 1966, vol. 59, pp. 352–55.