Levin, H. L. (1999). Ancient invertebrates and their living relatives. Prentice Hall.
Chicago-viite (17. p.)Levin, Harold L. Ancient Invertebrates and Their Living Relatives. Upper Saddle River, N.J: Prentice Hall, 1999.
MLA-viite (9. p.)Levin, Harold L. Ancient Invertebrates and Their Living Relatives. Prentice Hall, 1999.
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