general editors, Vladimir Gsovski and Kazimierz Grzybowski
Atlantic Books, 1959
Buku Teks SO
Atlantic Books, 1959
Buku Teks
by the Economist Intelligence Unit and the Cartographic Dept. of the Clarendon Press
Oxford University Press, 1956
Buku Referensi
Ryans, John K.
Ohio Kent State University Press , 1974
Buku Teks SO
edited by John Odmark
John Benjamins B.V. , 1979/1980/1981/1982
Buku Teks SO