Artikel Jurnal
Mehas, Kay Yockey
Glencoe/McGraw-Hill, 1997
Buku Teks
International Institute For Applied Systems Analysis, 1981
Buku Teks
Buckle, K.A.
Penerbit Universitas Indonesia (UI-Press), 1985
Buku Teks
Lee, Dong Sun
CRC Press, Taylor & Francis Group, 2008
Buku Teks