Hallock, S. A. (2013). The world in the twentieth century: A thematic approach. Pearson.
Lua i Stíl Chicago (17ú heag.)Hallock, Stephanie A. The World in the Twentieth Century: A Thematic Approach. Boston [u.a.]: Pearson, 2013.
Lua MLA (8ú heag.)Hallock, Stephanie A. The World in the Twentieth Century: A Thematic Approach. Pearson, 2013.
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