King, Michael
Hodder and Stoughton, 1988
Buku Teks SO
edited by Horace Belshaw
University of California Press, 1947
Buku Teks SO
Thakur, Ramesh
London: Westview Press, 1986,
Buku Referensi
Departement of Statistics, 1990
Buku Referensi
O`Sullivan, Vincent
Viking, [1988]
Buku Teks SO