Gaya APA
Hutabarat, I, H, N.
(2014).
The Power of Enthusiasm
(
Edisi 1)
.
Jakarta,:
Andi Offset.
Gaya MLA
Hutabarat, Ir., Herdy, N..
"The Power of Enthusiasm".
Edisi 1
Jakarta,:
Andi Offset,
2014.
Buku Teks.