Sheller, W. D. (1991). Welcome to English: Work Book 4/ Willard D.Shelleer; Susan C.Bayley. Indonesia : English Language Services Inc..
Chicago-viite (17. p.)Sheller, Willard D. Welcome to English: Work Book 4/ Willard D.Shelleer; Susan C.Bayley. Indonesia : English Language Services Inc., 1991.
MLA-viite (8. p.)Sheller, Willard D. Welcome to English: Work Book 4/ Willard D.Shelleer; Susan C.Bayley. Indonesia : English Language Services Inc., 1991.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.