Magdoff, Harry
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Buku Teks
Bowie, Robert R
ColumbiaUniversity Press, 1964
Buku Teks
Rüland, Jürgen, 1953-, author
Stanford University Press, 2018
Buku Teks
Artikel Jurnal
McGuire, Mark F., author
University of Minnesota, 1989
Buku Teks