Yakuza: Japan's Criminal Underworld: Kaplan, David E., Dubro, Alec
The Outsider: your average Yakuza wouldn't recognise himself in
Yakuza: Japan's Criminal Underworld by David E. Kaplan
The yakuza: Inside Japan's murky criminal underworld
Yamaguchi-gumi - Wikipedia
Tattoos in Japan: Why they're so tied to the yakuza - BBC News
Entertainment Voice
Yakuza: Japanese mafia launches magazine that's just for gangsters
Yakuza - Wikipedia
Crime and the City: Kyoto ‹ CrimeReads
What order should you play the Yakuza games?