Cita APA (7a ed.)

Ehrlich, P. R., & Ornstein, R. E. (2010). Humanity on a tightrope: Thoughts on empathy, family, and big changes for a viable future. Rowman & Littlefield : Distributed by National Book Network.

Cita Chicago Style (17a ed.)

Ehrlich, Paul R., y Robert E. Ornstein. Humanity on a Tightrope: Thoughts on Empathy, Family, and Big Changes for a Viable Future. Lanham, Md.: Rowman & Littlefield : Distributed by National Book Network, 2010.

Cita MLA (9a ed.)

Ehrlich, Paul R., y Robert E. Ornstein. Humanity on a Tightrope: Thoughts on Empathy, Family, and Big Changes for a Viable Future. Rowman & Littlefield : Distributed by National Book Network, 2010.