1. ADB. (2017). Meeting Asia’s infrastructure needs. Asian Development Bank.
2. Arase, D. (1995). Buying power: The political economy of Japan's foreign aid. Lynne Rienner Publishers.
3. Cabinet office. (2002). Gaikō ni kansuru seronchōsa 2002 [In Japanese: Opinion poll on diplomacy 2002] Retrieved May 25, 2022, from https://survey.gov-online.go.jp/index-gai.html
4. Cabinet office. (2004). Gaikō ni kansuru seronchōsa 2004 [In Japanese: Opinion poll on diplomacy 2004] Retrieved May 25, 2022, from https://survey.gov-online.go.jp/index-gai.html
5. Cabinet office. (2016). Gaikō ni kansuru seronchōsa 2016 [In Japanese: Opinion poll on diplomacy 2016] Retrieved May 25, 2022, from https://survey.gov-online.go.jp/index-gai.html