Gaya APA
Langford, S, R., Purnomo, Y, D, S. (1990).
Libya the Gulf of sirte closing line .
Durham:
Boundaries Research Press.
Gaya MLA
Langford, Stephen, R.., Purnomo, Yosef, Dwi, Sigit.
"Libya the Gulf of sirte closing line".
Durham:
Boundaries Research Press,
1990.
Text.