Abbs, B., & Freebairn, I. (1997). Blueprint one (20a. ed.). Longman.
Cita Chicago (17th ed.)Abbs, Brian, i Ingrid Freebairn. Blueprint One. 20a. ed. Essex: Longman, 1997.
Cita MLA (9th ed.)Abbs, Brian, i Ingrid Freebairn. Blueprint One. 20a. ed. Longman, 1997.
Atenció: Aquestes cites poden no estar 100% correctes.