Roberts, R.S., author
Elex Media Komputindo, 1981
Buku Referensi
Artikel Jurnal
Hinca IP Panjaitan ... [and others]
Internews Indonesia, 2000
Buku Teks
Lambrechts, Wynand, author
Springer Nature, 2019
eBooks
edited by C. Matzler
Institution of Engineering and Technology, 2006
eBooks