Cita APA (7a ed.)

Peña, L. (1984). Identity, fuzziness and noncontradiction. [s.n.].

Cita Chicago Style (17a ed.)

Peña, Lorenzo. Identity, Fuzziness and Noncontradiction. [S.l.]: [s.n.], 1984.

Cita MLA (9a ed.)

Peña, Lorenzo. Identity, Fuzziness and Noncontradiction. [s.n.], 1984.