Gaya APA

Sis, P. (2003). The tree of life : a book depicting the life of Charles Darwin naturalist, geologist dan thinker (1). USA: Enslow Publishers, Inc.

Gaya MLA

Sis, Peter. "The tree of life : a book depicting the life of Charles Darwin naturalist, geologist dan thinker". 1 USA: Enslow Publishers, Inc, 2003. Text.