edited by Mary Briody Mahowald
Hackett, 1994
Buku Teks SO
David Hay
London : Routterworths, 1993,
Buku Referensi
Lu, Yu
Hunan People Publishing House, 2009
Buku Teks
Quinn, K
New York Harcourt 1946
Buku Teks
edited by Stanley Aronowitz and Michael Roberts
John Wiley & Sons, 2018
Buku Teks SO