1. Alexander, L. E.: X-ray diffraction methods in polymer science. New York: John Wiley and Sons Inc. 1969.
2. Andrews, R. D.: Measurement of orientation in polystyrene monofilaments by means of double refraction. J. Appl. Phys. 25, 1223 (1954).
3. American Society of Testing Materials, Part 15. ASTM Designation F89–68 (1969).
4. Ballou, J. W., Silverman, S.: Sound velocity measurements. Textile Res. J. 14, 282 (1944).
5. Beer, M.: Quantitative interpretation of infrared dichroism in partly oriented polymers. Proc. Roy. Soc. (London), A236, 136 (1956).