
Source: 1850s, An Investigation of the Laws of Thought (1854), p. i; Preface, lead paragraph
Letter to Christoffer Hansteen (1826) as quoted by Øystein Ore, Niels Henrik Abel: Mathematician Extraordinary (1957) & in part by Morris Kline, Mathematical Thought from Ancient to Modern Times (1972) citing Œuvres, 2, 263-65
Source: 1850s, An Investigation of the Laws of Thought (1854), p. i; Preface, lead paragraph
As quoted in Bigeometric Calculus: A System with a Scale-Free Derivative (1983) by Michael Grossman, and in Single Variable Calculus (1994) by James Stewart.
The Differential and Integral Calculus (1836)
Letter to Dr. Bostock (June, 1798) as quoted by George Peacock, Life of Thomas Young (1855)
British Agricultural Bulletin 4, 217–218, 1951.
1950s
(A.J. Broomhall. Hudson Taylor and China’s Open Century, Book Four: Survivors’ Pact. London: Hodder and Stoughton and Overseas Missionary Fellowship, 1984, 297).
1990s and later, "The Institutional Structure of Production" (1992)
Quote from Boudin's letter to his friend Braquaval, 1 March 1895; as cited in 'The River Touques at Saint-Arnoult, 1895', by Anne-Marie Bergeret-Gourbin https://www.museothyssen.org/en/collection/artists/boudin-eugene/river-touques-saint-arnoult, Museo Thyssen
1880s - 1890s
Bilder's travel to Switzerland with some other artists was the longest travel he ever made in his short life
Source: 1850's, Vrolijk Versterven' (from Bilders' diary & letters), p. 23 - quote in Bilder's letter to his maecenas Johannes Kneppelhout, from Savoy, near Geneva, Switserland, September 1858;