APA (7th ed.) Citation

Bolton, W. F., & Crystal, D. (1969). The English language / by W.F. Bolton and D. Crystal. C.U.P..

Chicago Style (17th ed.) Citation

Bolton, W. F., and David Crystal. The English Language / by W.F. Bolton and D. Crystal. C.U.P., 1969.

MLA (9th ed.) Citation

Bolton, W. F., and David Crystal. The English Language / by W.F. Bolton and D. Crystal. C.U.P., 1969.

Warning: These citations may not always be 100% accurate.