1. Fast RA, Eckert CH (1988) 33rd Int SAMPE Symp 33: 369
2. Hergenrother PM, Rogalski ME, (1992) Polym Prep 33: 334
3. Grundschober F, Sambeth J (1968) US Pat 3,380,964
4. Bargain M, Combat A, Grosjean P (1968) Brit Pat Spec 1,190,718
5. Lubowitz HR (1970) USPat 3,528,950