Jonoobi M., Mathew A.P., Abdi M.M., Makinejad M.D., Oksman K. A Comparison of Modified and Unmodified Cellulose Nanofiber Reinforced Polylactic Acid (PLA) Prepared by Twin Screw Extrusion. 2012. Journal of Polymers and the Environment. 20. 4. 991-997. 10.1007/s10924-012-0503-9.