Cita APA (7a ed.)

Gorrell, R. M. (1963). Modern english workbook (2.). Prentice-Hall.

Cita Chicago Style (17a ed.)

Gorrell, Robert M. Modern English Workbook. 2. Estados Unidos: Prentice-Hall, 1963.

Cita MLA (9a ed.)

Gorrell, Robert M. Modern English Workbook. 2. Prentice-Hall, 1963.