1. Abe K (1991) A study on the united systems of Japan (Nihon No Toshi Taikei Kenkyu). Chijin Shobo Japan (in Japanese)
2. Abe K (1996) A study on the urban systems of the Advanced Countries (Senshinkoku No Toshi Taikei Kenkyu). Chijin Shobo, Japan (in Japanese)
3. Abe K (2001) A study on the urban systems of the developing companies (Hattentojokoku No Toshi Taikei Kenkyu). Chijin Shobo, Japan (in Japanese)
4. Abe K (2005) The evolution of the Korean urban system from the standpoint of large private firms’ Head and branch offices: 1985–2002. Geogr Rep Aichi Univ Educ 101:1–10 (in Japanese)
5. Abe K (2009) Major cities and urban systems of France from the standpoint of large private firms’ head and branch offices Bull Aichi Univ Educ 58:133–140 (in Japanese)