Lee, Hyung Woo, Rizki Insyani, Daniel Prasetyo, Hermawan Prajitno, and Johnner P. Sitompul. 2015. “Molecular Weight and Structural Properties of Biodegradable PLA Synthesized With Different Catalysts by Direct Melt Polycondensation”. Journal of Engineering and Technological Sciences 47 (4):364-73. https://doi.org/10.5614/j.eng.technol.sci.2015.47.4.2.