%0 Journal Article %T "Acid-catalyzed direct synthesis of methyl levulinate from paper sludge in methanol medium," %J BioResources %D 2015 %U https://www.ncsu.edu/bioresources/BioRes_08/BioRes_08_4_5895_Peng_LLC_Direct_Conver_Paper_Sludge_Methyl_Levulinate_4454.pdf