Cita APA (7a ed.)

Higgins, M. (1986). Elementary grammar workbook 1. Longman.

Cita Chicago Style (17a ed.)

Higgins, Muriel. Elementary Grammar Workbook 1. Essex: Longman, 1986.

Cita MLA (9a ed.)

Higgins, Muriel. Elementary Grammar Workbook 1. Longman, 1986.