1. 2) P.Fink-Jensen : “Hardness Testing of Organic Coatings” Appl. Chem. Div. Org. Coatings Section, IUPAC (1964)
2. 5) Gardner and Sward : “Phyisical and Chemical Examination”, p.158 (1950)
3. 8) p.Whiteley and G. W. Rothwell : 10 th FATIPEC, p.375 (1970)
4. 9) R. L. J. Morris and E. E. Longhust : 11 th FATIPEC, p.609 (1972)
5. 10) C. J. H. Monk and T. A. Wright : J. O. C. C. A., 48, 520 (1965)