1. K. Clusius: Z. Phys. Chem. Leipzig 3, 59 (1929)
2. J.N. Sherwood (ed.): The plastically Crystalline State (Orientationally Disordered Crystals) (Wiley, Chichester 1979)
3. N.E. Parsonage, L.A.K. Staveley: Disorder in Crystals (Clarendon, Oxford 1978)
4. G. Venkataraman, V.C. Sahni: Rev. Mod. Phys. 42, 409 (1970)
5. G. Dolling: Proceedings of the Conference on Neutron Scattering, Gatlinburg, USA, June 6–10, 1976, ed. by R.M. Moon, Vol. I, p. 263