1. K.J. PACKER, Progress in NMR spectroscopy, Vol.3 Pergamon (London) 1969.
2. H.A. RESING, Advances in Molecular Relaxation Processes, 1, 109, (1967)
3. H.A. RESING, Advances in Molecular Relaxation Processes, 3, 199 (1972).
4. J.J. FRIPIAT; Catalysis Review, 5, 269 (1971).
5. H. PFEIFER, NMR basic principlęs and progress, Vol. 7, Springer-Verlang;