Roberts, R., Gakonga, J., & Preshous, A. (2004). IELTS foundation: Student's book. Macmillan Education.

Roberts, Rachael, Joanne Gakonga, and Andrew Preshous. IELTS Foundation: Student's Book. Oxford: Macmillan Education, 2004.

Roberts, Rachael, et al. IELTS Foundation: Student's Book. Macmillan Education, 2004.