1. Zeolite Molecular Sieves: Structure;Breck,1974
2. J.T. Richardson, Principles of Catalysis Development, Plenum press. New York & London (1989).
3. J.R. Ugal, K.H. Hassan, I.H. Ali, J. Ass. of Arab Univ.for Basic and App. Sci. 9 (2010) 2–5.
4. Database of Zeolite Structures, (2002) /www.zeolites ethz.ch/zeolites / stdAtlas.htm.