Rousseas, Stephen
Alfred A. Knopf, 1972
Buku Teks SO
Hansen, Alvin Harvey, 1887-1975
Amacom, 1977
Buku Teks SO
Hansen, Alvin Harvey, 1887-1975
McGraw-Hill, 1949
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Walsh, Carl E.
MIT Press, 2010
Buku Teks SO
Cencini, Alvaro
Routledge , 1997
Buku Teks SO