english: Gallup’s success over the Literary Digest was a milestone the development of survey research (Converse 1987, Ch 3; Ohmer 2006, Ch 4; Igo 2008, Ch 3).
non_english: Sukses Gallup kang liwat Literary Digest minangka tonggak sejarah perkembangan riset survey (Converse 1987, Ch 3; Ohmer 2006, Ch 4; Igo 2008, Ch 3) .