1. Opechowski, W. and Guccione, R., Magnetism, ed. by Rado, S.T. and Suhl, H., volume IIA, Academic Press (New York, 1965).
2. Opechowski, W., Magnetic groups, North-Holland Publ. Comp. (Amsterdam), to be published.
3. Symmetry and Magnetism;Birss,1964
4. Magnetic Translation Group
5. Magnetic Translation Group. II. Irreducible Representations