Woodson, R. Dodge, author
McGraw-Hill, 1994
Buku Referensi
Babbitt, Harold E. (Harold Eaton), 1888-, author
McGraw-Hill, 1960
Buku Teks
Kuther, Tara L., editor
Wadsworth and Cengage Learning, 2012
Buku Teks
Artikel Jurnal
Library Association, 2000
Buku Teks