Usui, H. (2011). Ikkai de gokaku nihongo noryoku shiken n1 bunpo taisaku (First edition.). Takahashishoten.
Chicago Style (17th ed.) ZitazioaUsui, Hiromi. Ikkai De Gokaku Nihongo Noryoku Shiken N1 Bunpo Taisaku. First edition. Tokyo: Takahashishoten, 2011.
MLA (9th ed.) ZitazioaUsui, Hiromi. Ikkai De Gokaku Nihongo Noryoku Shiken N1 Bunpo Taisaku. First edition. Takahashishoten, 2011.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.