Cita APA (7a ed.)

Eckstut, S. (2000). Focus on grammar: A basic course for reference and practice : Workbook (2ª edición.). Longman.

Cita Chicago Style (17a ed.)

Eckstut, Samuela. Focus on Grammar: A Basic Course for Reference and Practice : Workbook. 2ª edición. New York: Longman, 2000.

Cita MLA (8a ed.)

Eckstut, Samuela. Focus on Grammar: A Basic Course for Reference and Practice : Workbook. 2ª edición. Longman, 2000.