Guareschi, Giovanni
Farrar, Straus & Young, 1953
Buku Teks
Blueprint, 1992
Buku Referensi
Findlay, Bruce Allyn
Stanford University Press, 1952
Buku Teks
Findlay, Bruce Allyn
Stanford University Press, 1959
Buku Teks
Braham, Lewis
McGraw-Hill, 2011
Buku Teks