(1) Factory under the Elms: A History of Harrisburg, New Hampshire 1774-1969 by John Bordon Armstrong ISBN: 9780262511704 MIT Press View at publisher
(2) Science Reference Sources, fifth edition by Frances B. Jenkins ISBN: 9780262600026 MIT Press View at publisher
(3) Theory and Observation of Normal Stellar Atmospheres: Proceedings of the Third Harvard-Smithsonian Converence on Stellar Atmosphere Edited by Owen Gingerich ISBN: 9780262070355 MIT Press View at publisher
(4) Megalithic Lunar Observatories Alexander Thom ISBN: 9780198581321 Oxford University Press View at publisher