HARRISON. E. R. (2012). FRANK MODERN CERTIFICATE BIOLOGY FOR MIDDLE SCHOOL WORKBOOK CLASS- 7 ( 2013- 14 ). FRANK BROS.
Chicago-viite (17. p.)HARRISON. E. R. FRANK MODERN CERTIFICATE BIOLOGY FOR MIDDLE SCHOOL WORKBOOK CLASS- 7 ( 2013- 14 ). FRANK BROS, 2012.
MLA-viite (9. p.)HARRISON. E. R. FRANK MODERN CERTIFICATE BIOLOGY FOR MIDDLE SCHOOL WORKBOOK CLASS- 7 ( 2013- 14 ). FRANK BROS, 2012.
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