Alexander, L, G. et al(2006).First Things First Students' Book : An Integrated Course for Beginners (Cet. 28).Yogyakarta:Penerbit Kanisius Publishing House.
Gaya MLA
Alexander, L., G. et al."First Things First Students' Book : An Integrated Course for Beginners".Cet. 28Yogyakarta:Penerbit Kanisius Publishing House,2006.Text.