Gaya APA

inc., E, B. et al (1997). The new encyclopaedia britannica volume 20 geomorphic to immunity Macropaedia knowledge in depth . : britanica.

Gaya MLA

inc., Encyclopaedia, Britannica,. et al. "The new encyclopaedia britannica volume 20 geomorphic to immunity Macropaedia knowledge in depth". : britanica, 1997. Text.