Okolie, Charles Chukwuma, author
Frederick A. Praeger, 1975
Buku Teks
Buku Teks
Gas, Beverly Witter Du, author
Prentice-Hall, 1999
Buku Teks
Du Gas, Beverly Witter, author
Prentice-Hall, 1999
Buku Teks
Tebbens, Henricus Duintjer, 1943-, author
Sijthoff & Noordhoff, 1980
Buku Teks