Bhakkhaphorn Booranasuntikul และ Naowarat Kanchanakhan. (2021) Effect of using smartphone before bedtime and sleep quality of middle-adulthood officers at Chulalongkorn University. <i>Chulalongkorn Medical Journal</i>, <i>65</i>(2), 137-145.Bhakkhaphorn Booranasuntikul และ Naowarat Kanchanakhan. "Effect of using smartphone before bedtime and sleep quality of middle-adulthood officers at Chulalongkorn University". Chulalongkorn Medical Journal 65 (2021):137-145.Bhakkhaphorn Booranasuntikul และ Naowarat Kanchanakhan. Effect of using smartphone before bedtime and sleep quality of middle-adulthood officers at Chulalongkorn University. Faculty of Medicine Chulalongkorn University:ม.ป.ท. 2021.