editor, John Gerard, Marcus Woodward
Senate, 1994
Buku Teks SO
Raven, Peter H.
Worth Publisher, 1986
Buku Referensi
Jozef Samaj, editor
[, Springer], 2012
eBooks
Gunther Witzany, editor
[, Springer-Verlag], 2012
eBooks
Bold, Harold Charles, 1909-
Harper & Row, 1957
Buku Teks SO