1. 1) Ministry of Health, Labour and Welfare. “Overview of the monthly vital statistics annual report, (approximate numbers) 2022.”: 〈https://www.mhlw.go.jp/toukei/saikin/hw/jinkou/geppo/nengai22/dl/gaikyouR4.pdf〉, cited 24 July, 2023.
2. 2) Nagaya M., Nakazawa S., J. Clin. Rehabil., 21, 855–862 (2012).
3. 3) Mc Gillicuddy A., Cream A. M., Sahm L. J., Eur. J. Clin. Pharmacol., 72, 141–151 (2016).
4. 4) Tomita T., Sakai A., Sato Y., Takanohashi S., Fukui T., Obara M., Nishimura N., Sasahara S., Tachiki H., Yoshida S., Kudo K., The Japanese Journal of Dysphagia Rehabilitation, 23, 37–43 (2019).
5. 5) Yamaguchi H., Ochiai A., Takiya H., Based on an abstract at the 24th Annual Meeting of Japanese Society of Pharmaceutical Sciences, Nagoya on 28 September, suppl., 371, 2014.