Gaya APA
Zeithaml, V, A. (1990).
Delivering quality service : balancing customer perceptions and expextations .
Malang:
Yayasan Indonesia Tera.
Gaya MLA
Zeithaml, Valarie, A..
"Delivering quality service : balancing customer perceptions and expextations".
Malang:
Yayasan Indonesia Tera,
1990.
.