1. J. Yang, H. Wang, S. Long et al., Engineering Plastic Application, 31, 63 (2003).
2. J. Yang, Y. Chen, Z. Yu et al., Polymer Materials Science and Engineering, 12, 52 (1996).
3. R. L. Bobsein, Jr., U.S. Pat. 4,808,698.
4. R. W. Campbell, U.S. Pat. 4,102,875.
5. R. W. Campbell, U.S. Pat. 4,016,145.