Smith, Adam
David Campbell Publishers, 1991
Buku Referensi
Smith, Adam
Modern Library, 1937
Buku Referensi
Pilling, David
Tim Duggan Books,, 2018
Buku Teks
Hall, Charles A.S.
[, Springer], 2012
eBooks
Frieden, Jeffry A.
Thomson Wadsworth, 2000
Buku Teks