Multhauf, R. P., & Lenzen, V. F. (2011). Development of Gravity Pendulums in the 19th Century Contributions from the Museum of History and Technology, Papers 34-44 On Science and Technology, Smithsonian Institution, 1966. Project Gutenberg.
Chicago Style (17th ed.) CitationMulthauf, Robert P., and Victor Fritz Lenzen. Development of Gravity Pendulums in the 19th Century Contributions from the Museum of History and Technology, Papers 34-44 On Science and Technology, Smithsonian Institution, 1966. Project Gutenberg, 2011.
MLA (9th ed.) CitationMulthauf, Robert P., and Victor Fritz Lenzen. Development of Gravity Pendulums in the 19th Century Contributions from the Museum of History and Technology, Papers 34-44 On Science and Technology, Smithsonian Institution, 1966. Project Gutenberg, 2011.