M. Kerekes, J. Varga, and G. Hardy, “INVESTIGATION OF SOLID PHASE POLYMERIZATION. XL. THE ROLE OF CRYSTALLOGRAPHIC FACTORS IN THE SOLID PHASE POLYMERIZATION OF N-VINYLPHTHALIMIDE”, Period. Polytech. Chem. Eng., vol. 22, no. 3, pp. 221–230, Jan. 1978.