Cita APA (7a ed.)

Rolf, B. (1981). Topics on vagueness. [s.n.].

Cita Chicago Style (17a ed.)

Rolf, Bertil. Topics on Vagueness. Lund: [s.n.], 1981.

Cita MLA (9a ed.)

Rolf, Bertil. Topics on Vagueness. [s.n.], 1981.