Citazione Stile APA (7a Edizione)

LEN, E., & YUE, P. (1988). Secondary 2 vocabulary guide and practice. reston Corporation.

Citazione stile Chigago Style (17a edizione)

LEN, Evelyn, e P.S YUE. Secondary 2 Vocabulary Guide and Practice. Singaphore: reston Corporation, 1988.

Citatione MLA (9a ed.)

LEN, Evelyn, e P.S YUE. Secondary 2 Vocabulary Guide and Practice. reston Corporation, 1988.