Honda, R. ., K. . Watanabe, and T. . Ozasa. “A Correspondence Analysis of Nine Japanese Historical English-As-a-Foreign-Language Textbooks”. International Journal of Learning, Teaching and Educational Research, vol. 16, no. 10, Oct. 2017, pp. 100-13, http://www.ijlter.net/index.php/ijlter/article/view/782.