1. New Egyptian resources of potable water and marine chemicals;Estefan;Chem. Ind. (London),1976
2. Ger. Offenlegungsschrift 2 008 847 (1970) to H. W. Dewittie, K. M. Atit and J. A. Kirchstein.
3. The recovery of sodium chloride from sea water
4. Belg. Patent 732 243 (1969) to S. Jerek.