1. Principles of Polymer Chemistry;Flory,1953
2. Hydrogels;Kudela,1985
3. Equation of swelling for polyelectrolyte gels;Katchalsky;J. Polym. Sci.,1951
4. Phase transitions of gels;Tanaka,1992
5. Structural Characteristics and Swelling Behavior of pH-Sensitive Hydrogels;Brannon,1988