1. R.J. Argauer and G.R. Landoldt, U.S. Patent 3 702 886 (1972).
2. Synthesis of High-silica Aluminosilicate Zeolites;Jacobs,1987
3. L. Marosi, T. Stabenow and M. Schwarzman, German Patent DOS 2 830 787 (1980).
4. L. Marosi, T. Stabenow and M. Schwarzman, German Patent DOS 3 006 471 (1981).