Cita APA (7th ed.)

Irwin, A. (1980). Stammering: A practical help for all ages. Penguin Books.

Cita Chicago (17th ed.)

Irwin, Ann. Stammering: A Practical Help for All Ages. Harmondsworth: Penguin Books, 1980.

Cita MLA (9th ed.)

Irwin, Ann. Stammering: A Practical Help for All Ages. Penguin Books, 1980.