APA (7th ed.) Citation

Turk, W. E., Beesley, M. J., & Thomson, J. (1969). Frequency conversion. Wykeham Publications.

Chicago Style (17th ed.) Citation

Turk, W. E., M. J. Beesley, and J. Thomson. Frequency Conversion. London [etc. ]: Wykeham Publications, 1969.

MLA (9th ed.) Citation

Turk, W. E., et al. Frequency Conversion. Wykeham Publications, 1969.