Németh, D., Z. Barta, J. Labidi, L. Gubicza, and K. Bélafi-Bakó. “ Study on Sorption Characteristics of Citric Acid Modified Rape-Seed Pellet Considering the Chemical Pre-Treatment Processes ”. Hungarian Journal of Industry and Chemistry, vol. 39, no. 3, Sept. 2011, pp. 407-11, doi:10.1515/457.