(2004) Young, Michael L. Dictionary of Polling: The Language of Contemporary Opinion Research (1992) The Gallup Legacy, from Gallup & Robinson website TIME profile from 1948
(2004) Young, Michael L. Dictionary of Polling: The Language of Contemporary Opinion Research (1992) 1936년 미국 대통령 선거 1948년 미국 대통령 선거 갤럽 (회사) Biography at Gallup.com The Gallup Legacy, from Gallup & Robinson website TIME profile from 1948