1. CIBA-Geigy systems: X 186/2476/HY 905; CY 221/HY 956; CY 221/HY 979; MY 790/Jeffamin D 230.
2. BASF Polyethylene 3428 and 3429 extruded material.
3. Hoechst (Ruhrchemie): GUR pressure sintered material.
4. Kanig G, Kolloid-Z.u.Z. Polymere 251, pp. 782–783 (1973). Kanig G, Progr. Colloid & Polymer Sci. 57, pp. 176–191 (1975)
5. Hartwig G, Wuechner F, Rev. Scient. Instr. 46, Nr. 4 (1975), p. 481.