edited by Zarine L. Rocha and Melinda Webber
Routledge, Taylor & Francis Group, 2018
Buku Teks SO
edited by Horace Belshaw
University of California Press, 1947
Buku Teks SO
Thakur, Ramesh
London: Westview Press, 1986,
Buku Referensi
Barber, Laurie
Century Hutchinson, 1989
Buku Teks
Sinclair, Keith
Penguin Books, 1986
Buku Teks SO