David Hilbert, "Mathematical Problems"., Bulletin of the American Mathematical Society, vol. 8, no. 10 (1902), pp. 437-479. Earlier publications (in the original German) appeared in Göttinger Nachrichten, 1900, pp. 253-297, and Archiv der Mathematik und Physik, 3dser. , vol. 1 (1901), pp. 44-63, 213-237.