Hardy, G. H., & Wright, E. M. (2004). An introduction to the theory of numbers (Fifth edition.). Oxford University Press.

Hardy, G. H., and Edward Maitland Wright. An Introduction to the Theory of Numbers. Fifth edition. Oxford ; New York: Oxford University Press, 2004.

Hardy, G. H., and Edward Maitland Wright. An Introduction to the Theory of Numbers. Fifth edition. Oxford University Press, 2004.