The effect of particle size and solvent type on the gallic acid yield obtained from Labisia pumila by ultrasonic extractionAfiqah Yeop, Jessinta Sandanasam, Sook Fun Pan, Sureena Abdulla, Mashitah M. Yusoff and Jolius GimbunMATEC Web Conf., 111 (2017) 02008DOI: https://doi.org/10.1051/matecconf/201711102008