Cita APA (7th ed.)

Maas, H. S., & Kuypers, J. A. (1974). From thirty to seventy. Jossey-Bass.

Cita Chicago (17th ed.)

Maas, Henry S., i Joseph A. Kuypers. From Thirty to Seventy. San Francisco: Jossey-Bass, 1974.

Cita MLA (9th ed.)

Maas, Henry S., i Joseph A. Kuypers. From Thirty to Seventy. Jossey-Bass, 1974.