Churchill, Winston, Sir, 1874-1965
Houghton Miffiln, 1948
Buku Teks SO
Arifin Djauhari
Fakultas Teknik Universitas Indonesia, [Date of publication not identified]
UI - Laporan Penelitian
Petrescu, Cezar
Foreign Languages Publishing House, 1957
Buku Teks SO
Fakultas Ilmu Sosial dan Ilmu Politik Universitas Indonesia, 2005
UI - Skripsi Membership
Freyberg, Annabel
Laurence King Publishing, ,
Buku Referensi