Sawhill, John C.
Harper's Magazine, 1979
Buku Teks
Sulistyoweni Widanarko, author
Fakultas Teknik Universitas Indonesia,
UI - Laporan Penelitian
Universitas Indonesia, 1967
UI - Publikasi
Brubacher, John S.
McGraw-Hill, 1965
Buku Teks
Kynghee University Press, 1975
Buku Teks