ERSÖZ, F., TOROS, A. B., AYDOĞAN, G., BEKTAŞ, H., ÖZCAN, Özhan, & ARIKAN, S. (2010). Assessment of anxiety levels in patients during elective upper gastrointestinal endoscopy and colonoscopy. Turkish Journal of Gastroenterology, 21(1), 29–33. https://doi.org/10.4318/tjg.2010.0044