Thitimon Lachaeku, Kamonluk Thongrod, Chuntisa Kaewkudsin, Chanyanut Sitnoi, Phutwadee Khunpirom, Suphattra Atthawan, Aubonratcha Kitwang, Areeyarin Chumrocnrucn and Promma, N. 2026. Factors influencing substance-use intentions among undergraduate students in northern Thailand: insights from the theory of reasoned action: 10.55131/jphd/2026/240115. Journal of Public Health and Development. 24, 1 (Jan. 2026), 200–214. DOI:https://doi.org/10.55131/jphd/2026/240115.