Παραπομπή APA

Ulmschneider, P. (2006). Intelligent life in the universe: Principles and requirements behind its emergence (2nd ed.). Springer-Verlag.

Παραπομπή Chicago Style

Ulmschneider, Peter. Intelligent Life in the Universe: Principles and Requirements Behind Its Emergence. 2nd ed. Berlin: Springer-Verlag, 2006.

Παραπομπή MLA

Ulmschneider, Peter. Intelligent Life in the Universe: Principles and Requirements Behind Its Emergence. 2nd ed. Springer-Verlag, 2006.