Sphaera - Peter Dollond answers Jesse Ramsden - A review of the events of the invention of the achromatic doublet with emphasis on the roles of Hall, Bass, John Dollond and others.
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Edgar, James S.; et al., eds. (2023). Observers' Handbook (annual) (USA ed.). Royal Canadian Astronomical Society (published October 2021). ISBN978-1-92-787930-6. Retrieved 2024-05-10.