Cita APA (7th ed.)

Hofer, H. (1991). Insight guides: Singapore. APA Pub.

Cita Chicago (17th ed.)

Hofer, Hans. Insight Guides: Singapore. Singapore: APA Pub, 1991.

Cita MLA (9th ed.)

Hofer, Hans. Insight Guides: Singapore. APA Pub, 1991.