APA (7th ed.) Citation

Jensen, V. A., & Olsen, I. S. (1959). Lars-Peter's birthday. Abingdon Press.

Chicago Style (17th ed.) Citation

Jensen, Virginia Allen, and Ib Spang Olsen. Lars-Peter's Birthday. New York: Abingdon Press, 1959.

MLA (8th ed.) Citation

Jensen, Virginia Allen, and Ib Spang Olsen. Lars-Peter's Birthday. Abingdon Press, 1959.