Cita APA (7a ed.)
Keen, D. (1994). Developing vocabulary skills (2a ed.). Heinle, cengage learning.
Cita Chicago Style (17a ed.)
Keen, Dennis. Developing Vocabulary Skills. 2a ed. Boston: Heinle, cengage learning, 1994.
Cita MLA (9a ed.)
Keen, Dennis. Developing Vocabulary Skills. 2a ed. Heinle, cengage learning, 1994.
Precaución: Estas citas no son 100% exactas.