T. N. Y. Nguyen, T. Y. N. Nguyen, T. M. T. Tran, T. V. Nguyen, N. P. L. Tran, and H. V. T. Luong, “Synthesis of lignin-based phenol-formaldehyde adhesive - A sustainable alternative to petrochemical”, CTU J. of Inn. & Sus. Dev., vol. 13, no. 3, pp. 48-57, Nov. 2021.