Siregar, Sylvia Veronica Nalurita Purnama, author
[publisher not identified], 2005
Artikel Jurnal
Kent, Raymond P.
Richard D. Irwin, INC, 1960
Buku Teks
Artikel Jurnal
Foster, Louis O., author
Chelton, 1961
Buku Teks
Ferris, Kenneth R., author
Richard D. Irwin, 1990
Buku Teks