Gallagher, N. (2005). Delta's key to the next generation TOEFL test: Advanced skill practice for the iBT. Delta Pub.
Chicago-referens (17:e uppl.)Gallagher, Nancy. Delta's Key to the Next Generation TOEFL Test: Advanced Skill Practice for the IBT. McHenry, IL: Delta Pub, 2005.
MLA-referens (9:e uppl.)Gallagher, Nancy. Delta's Key to the Next Generation TOEFL Test: Advanced Skill Practice for the IBT. Delta Pub, 2005.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.