Sinthorn, Poramin, and Supakorn Tirapat. “A Study of the Properties of Asphalt Mixed With Hard-Resin of Yang Na (Dipterocapus Alatus)”. The 28th National Convention on Civil Engineering, vol. 28, July 2023, pp. INF12-1, https://conference.thaince.org/index.php/ncce28/article/view/2475.