Gaya APA
Khalid, K, M.
(2014).
'Umar Ibn Al-Khaththab: Khalifah Penegak Keadilan
.
Bandung:
Mizania.
Gaya MLA
Khalid, Khalid, Muhammad.
"'Umar Ibn Al-Khaththab: Khalifah Penegak Keadilan".
Bandung:
Mizania,
2014.
Text.