Downie, George, author
Churchill Livingstone, 2010
Buku Teks
Gahart, Betty L., author
Mosby Elsevier, 2010
Buku Teks
Gahart, Betty L., author
ElSEVIER Mosby, 2012
Buku Referensi
Karuzina, I.
"Moscow: Mir Publishers, 1969",
Buku Teks
Johnson, Grace G., author
Appleton Century, 1986
Buku Teks