Ryuji WAKUTA. Profitability, Customer Satisfaction and Promotion in the Service Industry: A Comparative Study of Life Insurance and Professional Sports Services In Japan. Kyoto Management Review. 2023. 42. 61-80
WAKUTA Ryuji. Profitability and Frequency of Attendance for Orchestras: An Issue of Arts Marketing Studies. The Faculty of Economics and Business Administration Journal Kyoto Gakuen University. 2016. 2. 1-19
Profitability and Customer Retention Rate: Comparative Study between Financial Services and Professional Sports in Japan
(Sport Management Association of Australia and New Zealand Conference 2019 2019)