¹For more information about the algebraic structure and properties of finite fields, see, for example, S. Lang, Algebra, Second Edition, New York: Addison-Wesley Publishing Company, Inc., 1984, ISBN 0 201 05487 6; or R. Lidl, H. Niederreiter, Finite Fields, Encyclopedia of Mathematics and Its Applications, Vol. 20, Cambridge: Cambridge Univ. Press, 1983, ISBN 0 521 30240 4.