APA (7th ed.) Citation

Powell, M. J. D. (1981). Approximation theory and methods. Cambridge University Press.

Chicago Style (17th ed.) Citation

Powell, M. J. D. Approximation Theory and Methods. Cambridge [England] ; New York: Cambridge University Press, 1981.

MLA (9th ed.) Citation

Powell, M. J. D. Approximation Theory and Methods. Cambridge University Press, 1981.