Freedman, R. A. (2005). Universe: Student. New York: W. H. Freeman and Company.
Trích dẫn kiểu ChicagoFreedman, Roger A. Universe: Student. New York: W. H. Freeman and Company, 2005.
MLA CitationFreedman, Roger A. Universe: Student. New York: W. H. Freeman and Company, 2005.
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