Riley, Matilda White
Harcourt, Brace and world, 1963
Buku Teks
Rose, Gerry, author
Macmillan, 1982
Buku Teks
edited by Martin Bulmer
Macmillan, 1984
Buku Teks
Havet, Jacques
Mouton, 1970
Buku Teks
Denzin, Norman K., author
McGraw-Hill, 1978
Buku Teks