Cita APA (7a ed.)

Barnard, J. W. (1990). Exxon collides with the Valdez Principles. [s.n.].

Cita Chicago Style (17a ed.)

Barnard, Jayne W. Exxon Collides with the Valdez Principles. [S.l.]: [s.n.], 1990.

Cita MLA (9a ed.)

Barnard, Jayne W. Exxon Collides with the Valdez Principles. [s.n.], 1990.