APA (7th ed.) Citation

Powell, P., & Timms, P. L. The chemistry of the non-metals.

Chicago Style (17th ed.) Citation

Powell, P., and Peter L. Timms. The Chemistry of the Non-metals.

MLA (9th ed.) Citation

Powell, P., and Peter L. Timms. The Chemistry of the Non-metals.

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