Mary Jones. (2012). Cambridge Checkpoint Science Workbook 7. CAMBRIDGE UNIVERSITY PRESS.
Chicago-čujuhus (17. p.)Mary Jones. Cambridge Checkpoint Science Workbook 7. CAMBRIDGE UNIVERSITY PRESS, 2012.
MLA-čujuhus (9. p.)Mary Jones. Cambridge Checkpoint Science Workbook 7. CAMBRIDGE UNIVERSITY PRESS, 2012.
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