1. Stone H (1998) In: Frisch KC, Klempner D, Prentice G (eds) Advanced in plastic recycling: recycling of polyurethanes, vol 1. Technomic Publishing Company, Lancester, pp 167–222
2. Stone H, Villwock R, Martel B (2000) Polyurethanes conference. API, Boston
3. Behrendt G, Naber BW (2009) J University Chem Technol Metall 44:3
4. Nikje MMA, Nikrah M, Aga Mohammadi FH (2008) J Cell Plast 44:367
5. Benes H, Rosner J, Holler P, Synkova H, Kotek J, Horak Z (2007) Polym Adv Technol 18:149