„The First Photograph – Heliography”. Архивирано из оригинала 06. 10. 2009. г. Приступљено 29. 09. 2009. „from Helmut Gernsheim's article, "The 150th Anniversary of Photography," in History of Photography, Vol. I, No. 1, January 1977..In 1822, Niépce coated a glass plate... The sunlight passing through... This first permanent example... was destroyed... some years later.”
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„The First Photograph – Heliography”. Архивирано из оригинала 06. 10. 2009. г. Приступљено 29. 09. 2009. „from Helmut Gernsheim's article, "The 150th Anniversary of Photography," in History of Photography, Vol. I, No. 1, January 1977..In 1822, Niépce coated a glass plate... The sunlight passing through... This first permanent example... was destroyed... some years later.”
