Cita APA (7a ed.)

Humphrey, M., & Humphrey, H. (1988). Families with a difference: Varieties of surrogate parenthood. Routledge.

Cita Chicago Style (17a ed.)

Humphrey, Michael, y Heather Humphrey. Families with a Difference: Varieties of Surrogate Parenthood. London [etc.]: Routledge, 1988.

Cita MLA (9a ed.)

Humphrey, Michael, y Heather Humphrey. Families with a Difference: Varieties of Surrogate Parenthood. Routledge, 1988.