Ember, Carol R., author
Prentice-Hall, 1988
Buku Teks
Ember, Carol R.
Prentice-Hall, 1985
Buku Teks
Nanda, Serena, author
Wadsworth, 2002
Buku Teks
Miller, Barbara D., author
Pearson Education, 2005
Buku Teks
Hammond, Peter, author
Macmillan, 1978
Buku Teks