Gallwey, Timothy Josep
CRC Press, Taylor & Francis Group, 2009
Buku Teks
Sousa, John J.
Rhode Island Consortium, 1990
Buku Teks
Harley, John P.
McGraw-Hill Book, 2000
Buku Teks
Semishin, Vasilii Ivanovich
Peace, [date of publication not identified]
Buku Teks
Leith, John D.
Burgess, 1970
Buku Teks