Booranasuntikul, Bhakkhaphorn, and Naowarat Kanchanakhan. 2021. “Effect of using smartphone before bedtime and sleep quality of middle-adulthood officers at Chulalongkorn University”. Chulalongkorn Medical Journal 65 (2). Bangkok, Thailand. https://he05.tci-thaijo.org/index.php/CMJ/article/view/1079.