Kolevzon, Edward R.
Our world and its people
Allyn and Bacon, 1959
 Buku Teks
Our world's heritage
National Geographic Book Service.
National Geographic Society, 1987
 Buku Referensi
Gaunt, Jeremy
Our world now : Reuters
Thames & Hudson, 2010
 Buku Referensi
Inventors and discoverers : changing our world
National Geographic Book Service
National Geographic Society, 1988
 Buku Referensi
Tro, Nivaldo J.
Chemistry in focus : a molecular view of our world
Thomson, Brooks/Cole, 2007
 Buku Teks