APA (7e ed.) Bronvermelding

Sheller, W. D. (1991). Welcome to English: Work Book 4/ Willard D.Shelleer; Susan C.Bayley. Indonesia : English Language Services Inc..

Chicago (17e ed.) Bronvermelding

Sheller, Willard D. Welcome to English: Work Book 4/ Willard D.Shelleer; Susan C.Bayley. Indonesia : English Language Services Inc., 1991.

MLA (8e ed.) Bronvermelding

Sheller, Willard D. Welcome to English: Work Book 4/ Willard D.Shelleer; Susan C.Bayley. Indonesia : English Language Services Inc., 1991.