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2. Observation. Dictionary.com. Accessed 18 Jul. 2020. https://www.dictionary.com/browse/observation?s=t Observation. Dictionary.com. Accessed 18 Jul. 2020. https://www.dictionary.com/browse/observation?s=t
3. Is Seeing Believing?: Observation in Physics
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5. Giancoli Douglas C. 2008. Physics for scientists and engineers with modern physics. Pearson Prentice Hall. ISBN-10: 0131495089 Giancoli Douglas C. 2008. Physics for scientists and engineers with modern physics. Pearson Prentice Hall. ISBN-10: 0131495089