Chatchawan Wongjitrat และ Nattakarn Wongjitrat. (2013) Etiology of upper gastrointestinal bleeding at HRH Princess Maha Chakri Sirindhorn Medical Center. <i>Journal of Medicine and Health Sciences</i>, <i>20</i>(1), 46-52.Chatchawan Wongjitrat และ Nattakarn Wongjitrat. "Etiology of upper gastrointestinal bleeding at HRH Princess Maha Chakri Sirindhorn Medical Center". Journal of Medicine and Health Sciences 20 (2013):46-52.Chatchawan Wongjitrat และ Nattakarn Wongjitrat. Etiology of upper gastrointestinal bleeding at HRH Princess Maha Chakri Sirindhorn Medical Center. Faculty of Medicine,Srinakharinwirot University:ม.ป.ท. 2013.