Ramdan Pelana
Teknik dasar olahraga panahan
Rajawali Press, 2019
 Buku Teks
Mahathir bin Mohamad, 1925-
The challenge
Pelanduk Publications, 1986
 Buku Teks
Myrdal, Gunnar, 1898-
Challenge to affluence
Pantheon Books, 1963
 Buku Teks
Engler, Richard E.
The challenge of diversity
Harper & Row, 1964
 Buku Teks
McCulloch, John I. B.
Challenge to the Americans
New York The Foreign Policy Association 1940
 Buku Teks