Penney, D. (2009). The earliest pendulum clocks: A re-evaluation.
Chicago Style (17th ed.) CitationPenney, David. The Earliest Pendulum Clocks: A Re-evaluation. 2009.
MLA (9th ed.) CitationPenney, David. The Earliest Pendulum Clocks: A Re-evaluation. 2009.
Warning: These citations may not always be 100% accurate.