Cita APA (7a ed.)

Duffley, P. J. (1992). The English infinitive. Longman.

Cita Chicago Style (17a ed.)

Duffley, Patrick J. The English Infinitive. London [etc.]: Longman, 1992.

Cita MLA (9a ed.)

Duffley, Patrick J. The English Infinitive. Longman, 1992.