Vannevar Bush (1945). As We May Think. The Atlantic Monthly, vol. 176(1), pp. 101-108.
Drawing of Bush's theoretical memex machine was published in Life Magazine, November 19, 1945, vol. 19(11), p. 123, also under the title «As we may think». Since I have not found an image of the original article, I'll use the one circulating in many different places that have paid homage to Bush vision.
PS - From Memex To Hypertext arrived (same picture in p. 109)