1. H.R. Allcock, Phosphorus-Nitrogen Compounds, Academic Press, New York, 1972.
2. K. Brandt, I. Porwolik-Czomperlik, M. Siwy, T. Kupka, R.A. Shaw, D.B. Davies, R. Bartsch, J. Incl. Phenom. Macro. Chem. 35 (1999) 281.
3. E.W. Ainscough, A.M. Brodie, R.J. Davidson, C.A. Otter, Inorg. Chem. Commu. 11 (2008) 171.
4. C. Nataro, C.N. Myer, W.M. Cleaver, C.W. Allen, J. Organomet. Chem. 637-639 (2001) 284.
5. V. Chandrasekhar, B.M. Pandian, R. Azhakar, Polyhedron 27 (2008) 255.