Hans-Werner Franz, editor
Challenge social innovation : potentials for business, social entrepreneurship, welfare and civil society
[, Springer], 2012
 eBooks
Aubrey, Henry G.
Coexistence: economic challenge and response
National Planning Association, 1961
 Buku Teks
International business : the challenge of global competition
Donald A Ball, McCulloch, Jr., Wendell H., J Michael Geringer, Michael S Minor, Jeanne M NcNett
McGraw-Hill, Irwin, 2008
 Buku Teks
Japan's small business the new challenge
Japan Small Business Research Institute , 1995
 Buku Teks
Ball, Donald A.
International business : the challenge of global competition
Irwin McGraw-Hill, 1999
 Buku Teks