1. Pauthenet, R., Bochirol, L.: J. Phys. Radium 12 (1951) 249.
2. Smit, J., Wijn, H.P.J.: Adv. Electron. Electron. Phys. 6 (1954) 69.
3. Gorter, E.W.: Usp. Fiz. Nauk 57 (1955) 279.
4. Durif-Varambon, A., Bertaut, E.F., Pauthenet, R.: Ann. Chim. (Paris) 13 (1956) 526.
5. Durif-Varambon, A., Bertaut, E.F., Pauthenet, R.: Ann. Chim. (Paris) 13 (1956) 34.