APA (7th ed.) Citation

Hines, W. G., & De Levie, R. (2010). The early development of electronic pH meters.

Chicago Style (17th ed.) Citation

Hines, Wallis G., and Robert De Levie. The Early Development of Electronic PH Meters. 2010.

MLA (9th ed.) Citation

Hines, Wallis G., and Robert De Levie. The Early Development of Electronic PH Meters. 2010.

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