61. Jeong SY, Ma YD, Polym.(Korea), 31(1), 58 (2007)
62. Chiellini E, Laus M, Handbook of Liquid Crystals, Demus D, Goodby J, Gray GW, Spiess HW, Vill V, Editors, Wiley-VCH, Weinheim-New York, Vol 3, Chap. 2, p 26 (1998)
63. Tokita M, Watanabe J, Polym. J., 38, 611 (2006)