TWIST, C. Encyclopedia of science: Life on earth fossils and human ancestors the basics of life. Volume IV. Macmillan Publishing Company.
Chicago-viite (17. p.)TWIST, Clint. Encyclopedia of Science: Life on Earth Fossils and Human Ancestors the Basics of Life. Volume IV. Macmillan Publishing Company.
MLA-viite (8. p.)TWIST, Clint. Encyclopedia of Science: Life on Earth Fossils and Human Ancestors the Basics of Life. Volume IV. Macmillan Publishing Company.
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