Cita APA (7a ed.)

Obee B. Bob & Evans V. Virginia. (2010). Upstream. Upper Intermediate B2+: Teacher's Book (5th ed.). Newbury, Express Publishing, 2010.

Cita Chicago Style (17a ed.)

Obee B. Bob y Evans V. Virginia. Upstream. Upper Intermediate B2+: Teacher's Book. 5th ed. Newbury, Express Publishing, 2010, 2010.

Cita MLA (9a ed.)

Obee B. Bob y Evans V. Virginia. Upstream. Upper Intermediate B2+: Teacher's Book. 5th ed. Newbury, Express Publishing, 2010, 2010.