Cita APA (7a ed.)

Ashworth, J. A., & Clark, J. A. (1990). Stepping stones 3. Wing King Tong Company, Limited.

Cita Chicago Style (17a ed.)

Ashworth, Julie Autora, y John Autor Clark. Stepping Stones 3. 2-Hong Kong,China: Wing King Tong Company, Limited, 1990.

Cita MLA (9a ed.)

Ashworth, Julie Autora, y John Autor Clark. Stepping Stones 3. Wing King Tong Company, Limited, 1990.