Cita APA (7th ed.)

Porterfield, J. D., & St. Pierre, R. W. (1992). Healthful aging. Dushkin Pub. Group.

Cita Chicago (17th ed.)

Porterfield, James D., i Richard W. St. Pierre. Healthful Aging. Guilford, CT: Dushkin Pub. Group, 1992.

Cita MLA (9th ed.)

Porterfield, James D., i Richard W. St. Pierre. Healthful Aging. Dushkin Pub. Group, 1992.