Konig, Hartmut
Springer-Verlag, 2012
eBooks
Schwab, Klaus, 1938-
Currency, 2017
Buku Teks
edited by Frederick W. Moorman, revised by morris Palmer Tilley
DC Health, 1917
Buku Teks
Wright, Samson
Oxford University Press, 1931
Buku Referensi
Heragu, Sunderesh S.
Sunderesh S., 2016
Buku Teks