Sheller, W. D. (1991). Welcome to English: Work Book 4/ Willard D.Shelleer; Susan C.Bayley. Indonesia : English Language Services Inc..
Chicago-referens (17:e uppl.)Sheller, Willard D. Welcome to English: Work Book 4/ Willard D.Shelleer; Susan C.Bayley. Indonesia : English Language Services Inc., 1991.
MLA-referens (8:e uppl.)Sheller, Willard D. Welcome to English: Work Book 4/ Willard D.Shelleer; Susan C.Bayley. Indonesia : English Language Services Inc., 1991.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.