Cita APA (7th ed.)
Day, A. J., & Hoffman, V. (1991). The annual register: A record of world events 1990. Longman.
Cita Chicago (17th ed.)
Day, Alan J., i Verena Hoffman. The Annual Register: A Record of World Events 1990. London, [England]: Longman, 1991.
Cita MLA (9th ed.)
Day, Alan J., i Verena Hoffman. The Annual Register: A Record of World Events 1990. Longman, 1991.
Atenció: Aquestes cites poden no estar 100% correctes.