APA (7th ed.) Citation

Pflugfelder, H. O. (1990). Quasigroups and loops: Introduction. Heldermann Verlag.

Chicago Style (17th ed.) Citation

Pflugfelder, Hala O. Quasigroups and Loops: Introduction. Berlín: Heldermann Verlag, 1990.

MLA (9th ed.) Citation

Pflugfelder, Hala O. Quasigroups and Loops: Introduction. Heldermann Verlag, 1990.