1. Asahi Newspaper. March 16, 1994. Protect raccoon dogs!: a tunnel has been built (in Japanese)
2. Asahi Newspaper. June 20, 1996. Highways are raccoon dogs’ graveyards!? (in Japanese)
3. Asahi Newspaper. April 27, 1998. A big trouble, the Expressways across animals’ trails: 26,069 roadkills last year (in Japanese)
4. Durchlässe für Dachse und ihre Effectivät;Broekhuizen;Zeitschrift für Jagdwissenschaft,1996
5. Interstate highway roadkilled animals: a data source for biologists;Case;Wildlife Society Bulletin,1978