A guide to the old observatories at Delhi, Jaipur, Ujjain, Benares - Kaye, G. R. 1866-1929 (Superintendent Government Print., India, 1920)
Based upon the author's larger work "The astronomical observatories of Jai Singh," Calcutta, 1918, issued in the series of reports of the Archaeological survey of India, New imperial series, vol. XL.
Bibliography: p. 93-94