1. Strengthening of Glass Fibers: I, Cladding *
2. 2E. B. Shand , Glass Engineering Handbook , 2d ed. ; p.33 . McGraw-Hill Book Co., New York, 1958 .
3. 4J. S. Haggerty , "Thermal Expansion, Heat Capacity, Structural Relaxation Measurements in the Glass Transition Region "; Sc.D. Thesis , Massachusetts Institute of Technology, Cambridge, Mass., 1966 .
4. 5Properties of Selected Commercial Glasses ; p.15 . Corning Glass Works, Corning, New York, 1965 .