Pick, James B.
Westview , 1989
Buku Referensi
De Paredes, Ellen Shaw
Wolters Kluwer, Lippincott Williams & Wilkins, 2007
Buku Referensi
Dodd, Everett E.
McGraw-Hill, 1979
Buku Teks SO
editors by Young-Han Park
Sung Ji Hwa, 2006
Buku Referensi
Shepperd, William R.
Barnes and Noble, 1959
Buku Referensi