APA (7th ed.) Citation

CLAMP (Mangaka group), Kōdansha, & Mizushima, T. (2010). xxxholic. Kodansha.

Chicago Style (17th ed.) Citation

CLAMP (Mangaka group), Kōdansha, and Tsutomu Mizushima. Xxxholic. [United States?]: Kodansha, 2010.

MLA (8th ed.) Citation

CLAMP (Mangaka group), et al. Xxxholic. Kodansha, 2010.

Warning: These citations may not always be 100% accurate.