Journal of the Korean Society of Mathematical Education. Series B. The Pure and Applied Mathematics (J. Korean Soc. Math. Educ. Ser. B Pure Appl. Math.) (20240101), 31, no.~1, 49-56. ISSN: 1226-0657 (print).eISSN: 2287-6081.
Journal of the Korean Society of Mathematical Education. Series B. The Pure and Applied Mathematics (J. Korean Soc. Math. Educ. Ser. B Pure Appl. Math.) (20230101), 30, no.~1, 35-42. ISSN: 1226-0657 (print).eISSN: 2287-6081.