APA Style
Johns, C. (2013).
National Geographic : 100 Secret Journeys (Vol. 30 tahun 2013).
Washington:
National Geographic Society.
MLA Style
Johns, Chris.
"National Geographic : 100 Secret Journeys".
Vol. 30 tahun 2013
Washington:
National Geographic Society,
2013.
Perpustakaan KALBIS.