Boyd, Martin
Landsdowne Press, 1946
Buku Teks SO
Niall, Brenda
Oxford University Press, 1974
Buku Teks SO
Dhita Hapsarani
Fakultas Ilmu Pengetahuan Budaya Universitas Indonesia, 1988
UI - Skripsi Membership
Boyd, Martin
Lansdowne, 1965
Buku Teks SO
Carey, Peter
University of Queensland Press, 1988
Buku Teks SO