Sheeler, W. D. (1991). Welcome to English: Book 3/ Willard D. Sheller. Indonesia: English Language Services Inc..
Chicago-viite (17. p.)Sheeler, Willard D. Welcome to English: Book 3/ Willard D. Sheller. Indonesia: English Language Services Inc., 1991.
MLA-viite (8. p.)Sheeler, Willard D. Welcome to English: Book 3/ Willard D. Sheller. Indonesia: English Language Services Inc., 1991.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.