In the original published version of this article, duplicate page numbers were displayed in 5 references in the article. These have now been removed. The correct version of each reference as cited in the text can be found below. The publisher apologizes for the error. Both the HTML and PDF versions of the article have been updated to correct the error.
Page 2 (Spieldenner and Eguchi, 2019, p.143), (Martino and Pallotta-Chiarolli, 2006, p. 22).
Page 4 (UNESCO, 2016, p. 11).
Page 5 (Rasmussen, 2003, p. 35), (Eguchi, 2019, p. 85).