New horizons world guide : Pan American's Travel Facts about 108 countries
edited by Gerald W. Whitted
Pan American Airways, 1963
 Buku Teks SO
World Facts : countries of the world
Gedes & Grosset, 2001
 Buku Referensi
New horizons world guide
edited by Gerald W. Whitted
Pan American World Airways, 1971
 Buku Referensi
New horizons world guide
edited by Gerald W. Whitted
Pan American World Airways, 1963
 Buku Referensi
Pierce, Eleanor B.
New Horizons living abroad : Pan American's guide to living conditions in 90 countries/Eleanor B.Pierce
Pan American Airways, 1965
 Buku Teks SO