Artikel Jurnal
Lee, Grossman, author
Amacom, 1974
Buku Teks
edited by Jeanette Lancaster, Wade Lancaster
Mosby , 1982
Buku Teks
Marpaung, Togap, author
Sintesa Mandiri Karya, 2023
Buku Teks
edited by Jeanette Lancaster and Wade Lancaster
Mosby , 1982
Buku Teks