Eagan, Daniel (2011-11-24). America's Film Legacy, 2009-2010. Bloomsbury Publishing USA,. "... Edison hired William Heise, who had experience with similar machines, to assist Dickson. They built a horizontal-feed camera that exposed images on a 3/4-inch film strip. Small perforations helped move the film through the mechanism. / The first examples were viewed through a peephole
device Edison would market as the "Kinetoscope." Edison showed what later become known as Dickson Greeting to members of the Federation of Women'S Club on May 20, 1891." - Google books
Paul Spehr (2008-11-17). The Man Who Made Movies: W.K.L. Dickson. Indiana University Press. p. 208 - Google books
