Sycip, Gorres, Velajo & Utomo
Djakarta , Sycip, Gorres, Velayo & Utomo
Buku Teks SO
Beattie, C.N.
Stevens & Sons Lim, 1957
Buku Teks
Seltzer, Lawrence Howard
Columbia University Press, 1968
Buku Teks
Prentice-Hall, 1976
Buku Teks SO
Stanley, Joyce, 1901-
Warren, Gorham and Lamont, 1971
Buku Teks SO