1. 1 H. P. Hood and M. E. Nordberg , “Treated Borosilicate Glass,” U. S. Pat. 2,106,744 1938, February.
2. Ternary System Na2O-B2O3-SiO2;Morey;J. Soc. Glass Technol.,1951
3. 4 W. Vogel ; see Ref. 3, pp. 17-25.
4. Region of Anomalous Glasses in System Na2O-B2O3-SiO2;Molchanova;Steklo i Keram.,1957