1. 34Can: G. Canneri, “Alloys of Praseodymium and Silver,”Met. Ital., 26, 794 (1934).
2. 38Ian: A. Iandelli, “Crystal Structure of Alloys Composed of Intermetallic Compounds of the Rare-Earth Elements,” Atti 10th Congr. Int. Chim. Rome,2, 688–694 (1938) in Italian.
3. ANL-6099;A. E. Dwight,1959
4. 60Ian: A. Iandelli, “Intermetallic and Metalloid Gadolinium Compounds,”Atti Accad. Naz. Lincei Rend., Cl. Sci. Fis. Mat. Nat., 29, 62 (1960) in Italian.
5. 68Ian: A. Iandelli and A. Palenzona, “On the Occurrence of the MX 2 Phases of the Rare Earths with the IB, IIB, and IIIB Group Elements and Their Crystal Structures,”J. Less-Common Met., 15, 273 (1968).