Gultom, Ricky Janus Mangapul, author
Fakultas Teknik Universitas Indonesia, 2022
UI - Tugas Akhir
Erwin Frizi, author
Universitas Indonesia, 2014
UI - Skripsi (Membership)
Hindle, Brian Paul
B.T. Batsford Ltd, 1993
Buku Teks
Owen, Wilfred, author
Brookings Institution, 1951
Buku Teks
Stevenson, Maggie, author
Page one Publishing, 2002
Buku Referensi