Brinkley, Frank and Dairoku Kikuchi. (1915). A History of the Japanese People from the Earliest Times to the End of the Meiji Era,p. 203., p. 203, at Google Books; excerpt, "Muchimaro's home, being in the south (nan) of the capital, was called Nan-ke; Fusazaki's, being in the north (hoku), was termed Hoku-ke; Umakai's was spoken of as Shiki-ke, since he presided over the Department of Ceremonies (shiki), and Maro's went by the name of Kyō-ke, this term also having reference to his office."
Kimoto, Yoshinobu (2004). "『牛屋大臣』藤原是公について" [On "Ushiya-Daijin" Fujiwara no Korekimi]. 奈良時代の藤原氏と諸氏族 [The Fujiwara Clan and Other Clans of the Nara Period] (in Japanese). Ohfu.
Brinkley, Frank and Dairoku Kikuchi. (1915). A History of the Japanese People from the Earliest Times to the End of the Meiji Era. New York: Encyclopædia Britannica. OCLC 413099
