Salisbury, Harrison E., author
Harper & Row , 1962
Buku Teks
Thaden, Edward C.
John Wiley & Sons, 1971
Buku Teks
Salisbury, Harrison E., author
Atheneum, 1965
Buku Teks
Vernadsky, George
At The Clarendon Press, 1959
Buku Teks
Vernadsky, George
Yele University Press, 1953
Buku Teks